Display in fullcalendar title and description PHP JS

i have a problem with full calendar, i can’t display the description in a new line, currently i have created a title which is a concatenations of the title and the description stored in the database mysql, but it is messy, i want to display in the event block in one row the title and in one row the description

calendar

For example in the yellow event i want in the first line Primo Soccorso and in the second line Gruppo A….

Currently the data is load from json from php mysql code using ajax.

$query = "select * from listaeventi";
if($result = mysqli_query($conn,$query)){
  while($row = mysqli_fetch_array($result,MYSQLI_ASSOC)){

      $data[] = [
          'id'              => $row["id"],
          'title'           => $row["titoloEvento"]." , ".$row["descrizioneEvento"],
          'description'     => $row["descrizioneEvento"],
          'type'            => "Corso",
          'start'           => $row["dataInizio"],
          'end'             => $row["dataFine"],
          'durata'          => $row["durataEvento"],
          'address'         => $row["indirizzoEvento"],
          'city'            => $row["paeseEvento"],
          'cliente'         => $row["cliente"],
          'sala'            => $row["sala"],
          'data_successiva' => $row["data_successiva"],
          'iscrizione'      => $row["iscrizione"],
          'borderColor'     => $row["bgcolor"],
          'backgroundColor' => $row["bordercolor"]
      ];

  }

}

The js code for full calendar it is this

document.addEventListener('DOMContentLoaded', function() {
var url ='';

var vista = 'listMonth';
if(/Android|webOS|iPhone|iPad|iPod|BlackBerry|IEMobile|Opera Mini/i.test(navigator.userAgent)){
  var vista = 'listMonth';
}
    var calendarEl = document.getElementById('calendar');
    var calendar = new FullCalendar.Calendar(calendarEl, {
      initialView: vista,
      locale: 'it',
      headerToolbar: {
        left: 'prev,next,today',
        center: 'title',
        right: 'dayGridMonth,timeGridWeek,timeGridDay,listMonth',
      },
      buttonText: {
        today:    'Oggi',
        month:    'Mese',
        week:     'Settimana',
        day:      'Giorno',
        list:     'Agenda'
      },


      navLinks: true, // can click day/week names to navigate views
      editable: true,
      selectable: true,
      eventDisplay: 'block',
      selectMirror: true,
      dayMaxEvents: true, // allow "more" link when too many events
      events: url+'calendar/load.php?filtro='+filtroCorso,
      contentHeight: 1500,
      allDaySlot: false, //evento allday
      firstDay: 1,
      select: function(arg) {

        var options = {'weekday': 'long', 'month': 'long', 'day': '2-digit'};

        var date = arg.start.toLocaleString('it-IT', options);

        // $("#data_inizio").val(arg.start.getFullYear()+"-"+(arg.start.getMonth()+1)+"-"+addZero(arg.start.getDate())+" "+addZero(arg.start.getHours())+":"+addZero(arg.start.getMinutes())+":"+addZero(arg.start.getSeconds()));
        // $("#data_fine").val(arg.end.getFullYear()+"-"+(arg.end.getMonth()+1)+"-"+addZero(arg.end.getDate())+" "+addZero(arg.end.getHours())+":"+addZero(arg.end.getMinutes())+":"+addZero(arg.end.getSeconds()));
        //
        // $("#data_evento").text(date);
        // $("#data_italiana").val(date);
        //
        // $("#ora_inizio").text(addZero(arg.start.getHours())+":"+addZero(arg.start.getMinutes()));
        // $("#ora_fine").text(addZero(arg.end.getHours())+":"+addZero(arg.end.getMinutes()));

        calendar.unselect()
      },

      //eventDrop is triggered when an event is dragged and dropped to another date or time.
      eventDrop: function(arg) {
          var start = arg.event.start.toDateString()+' '+arg.event.start.getHours()+':'+arg.event.start.getMinutes()+':'+arg.event.start.getSeconds();
          if (arg.event.end == null) {
              end = start;
          } else {
              var end = arg.event.end.toDateString()+' '+arg.event.end.getHours()+':'+arg.event.end.getMinutes()+':'+arg.event.end.getSeconds();
          }

          // $.ajax({
          //   url:url+"calendar/update.php",
          //   type:"POST",
          //   data:{id:arg.event.id, start:start, end:end},
          // });
      },
      //eventReize is very similar, this is triggered when an event is manually resized from a week or day view.
      eventResize: function(arg) {
          var start = arg.event.start.toDateString()+' '+arg.event.start.getHours()+':'+arg.event.start.getMinutes()+':'+arg.event.start.getSeconds();
          var end = arg.event.end.toDateString()+' '+arg.event.end.getHours()+':'+arg.event.end.getMinutes()+':'+arg.event.end.getSeconds();

          // $.ajax({
          //   url:url+"calendar/update.php",
          //   type:"POST",
          //   data:{id:arg.event.id, start:start, end:end},
          // });
      },

      eventClick: function(arg) {

        var id = arg.event.id;
        var options = {'weekday': 'long', 'month': 'long', 'day': '2-digit'};

        var date = arg.event.start.toLocaleString('it-IT', options);

        $.ajax({
          url:url+"calendar/getevent.php",
          type:"POST",
          dataType: 'json',
          data:{id:arg.event.id},
          success: function(data) {
            // alert(data[0].city);

              // alert(data[0].idRiferimento);
              $('#tipoEvento').html(data[0].type);
              $('#tipoEvento').css('color', data[0].backgroundColor);

              $('#titoloEvento').html(data[0].title);
              $('#titoloEvento').css('color', data[0].backgroundColor);
              globalID = data[0].id;

              $("#eliminaData").attr("href","https://corsi.gpserviziarco.it/calendario-corsi/index.php?delete="+globalID);

              globalTitolo = data[0].title;
              globalBackgroundColor = data[0].backgroundColor;


              // SETTO MAPPA USCITE PRATICHE

              if(data[0].address.includes("Circolo") || data[0].address.includes("Conca")){
                $('#mappa').attr('src', "https://www.google.com/maps/embed?pb=!1m18!1m12!1m3!1d3324.708097095604!2d10.87475893318616!3d45.86273542875592!2m3!1f0!2f0!3f0!3m2!1i1024!2i768!4f13.1!3m3!1m2!1s0x478210e9aaef5bf7%3A0x2e3475f668003103!2sCircolo%20Vela%20Torbole!5e1!3m2!1sit!2sit!4v1727274256988!5m2!1sit!2sit");
                $('#indirizzo-mobile').attr('href', "https://maps.app.goo.gl/wMCmuxbFp6fCnEog6");
              }else if(data[0].address.includes("Porto")){
                $('#mappa').attr('src', "https://www.google.com/maps/embed?pb=!1m18!1m12!1m3!1d6647.5929025257!2d10.853839376647468!3d45.87797800573525!2m3!1f0!2f0!3f0!3m2!1i1024!2i768!4f13.1!3m3!1m2!1s0x478210d3a0a6edb3%3A0xd4ecc39b92163d32!2sPorto%20San%20Nicol%C3%B3!5e1!3m2!1sit!2sit!4v1727274370632!5m2!1sit!2sit");
                $('#indirizzo-mobile').attr('href', "https://goo.gl/maps/2gw4jFDzrbML83NE6");
              }else if(data[0].address.includes("San Nazzaro 2/D")){
                $('#mappa').attr('src', "https://www.google.com/maps/embed?pb=!1m18!1m12!1m3!1d3322.6874817366593!2d10.849190576648251!3d45.89651450448972!2m3!1f0!2f0!3f0!3m2!1i1024!2i768!4f13.1!3m3!1m2!1s0x4782114dad8eac25%3A0xec24e7cccdbb556f!2sG%20%26%20P%20Servizi%20Srl!5e1!3m2!1sit!2sit!4v1727274332071!5m2!1sit!2sit");
                $('#indirizzo-mobile').attr('href', "https://goo.gl/maps/2gw4jFDzrbML83NE6");
              }else if(data[0].address.includes("Croseta 39")){
                $('#mappa').attr('src', "https://www.google.com/maps/embed?pb=!1m18!1m12!1m3!1d3321.7411262686323!2d10.862404176648921!3d45.91232830342698!2m3!1f0!2f0!3f0!3m2!1i1024!2i768!4f13.1!3m3!1m2!1s0xaa3df96f0daec2f7%3A0x9c56bae78c563eac!2sFeelwork%20sicurezza%20verticale!5e1!3m2!1sit!2sit!4v1727274399004!5m2!1sit!2sit");
                $('#indirizzo-mobile').attr('href', "https://maps.app.goo.gl/1iJBxVWkjJTZqxD39");
              }else if(data[0].address.includes("Piazza Maria Contini")){
                $('#mappa').attr('src', "https://www.google.com/maps/embed?pb=!1m18!1m12!1m3!1d3322.7094054490444!2d10.844431726648251!3d45.896148104514396!2m3!1f0!2f0!3f0!3m2!1i1024!2i768!4f13.1!3m3!1m2!1s0x478216c504b123a3%3A0xdb7e711b80b3da0c!2sPiscina%20Comunale%20Coperta%20Enrico%20Meroni!5e1!3m2!1sit!2sit!4v1727274590307!5m2!1sit!2sit");
                $('#indirizzo-mobile').attr('href', "https://maps.app.goo.gl/Eyo5AvC5ZLU2zKTw9");
              }



              // FINE SETTO MAPPA USCITE PRATICHE

              $('#descrizioneEvento').html(data[0].description);
              globalDescrizione = data[0].description;

              $("#indirizzoEvento").html(data[0].address);
              $("#paeseEvento").html(data[0].city);

              $("#iscrizioneEvento").html(data[0].iscrizione);
              if(data[0].iscrizione=="APERTA"){
                $("#badge-iscrizione").removeClass( "badge-danger" );
                $("#badge-iscrizione").addClass( "badge-success" );
                $("#apriIscrizione").prop("disabled",false);
              }else if(data[0].iscrizione=="CHIUSA"){
                $("#badge-iscrizione").removeClass( "badge-success" );
                $("#badge-iscrizione").addClass( "badge-danger" );
                $("#apriIscrizione").prop("disabled",true);
              }

              if(data[0].title.includes("scit")){
                $("#apriIscrizione").hide();
              }else{
                $("#apriIscrizione").show();
              }


              $("#durataEvento").html(data[0].durata);

              $("#sala").html(data[0].sala);


              $("#lezioneSucccessiva").html(data[0].data_successiva);


              $("#dataEvento").text(date);
              $("#oraInizio").text(addZero(arg.event.start.getHours())+":"+addZero(arg.event.start.getMinutes()));
              $("#oraFine").text(addZero(arg.event.end.getHours())+":"+addZero(arg.event.end.getMinutes()));

              globalData = date+" "+addZero(arg.event.start.getHours())+":"+addZero(arg.event.start.getMinutes())+" - "+addZero(arg.event.end.getHours())+":"+addZero(arg.event.end.getMinutes());


              $("#pdf_specifico").attr("href", "docs/"+data[0].pdf+".pdf");

              $("#export-corso").attr("href", "/calendario-corsi/export.php?corso="+globalTitolo+"&data="+globalData);

              // $("#lista-iscritti").attr("href", "/calendario-corsi/lista-iscritti.php?corso="+globalTitolo+"&data="+globalData);
              $("#lista-iscritti").attr("href", "/calendario-corsi/lista-iscritti.php?corso="+globalTitolo+"&data="+data[0].dataOra+"&data2="+globalData); //NUOVO MODELLO DATA LISTA ISCRITTI
              $("#linkIscrizione").attr("href", "/calendario-corsi/iscrizione.php?type=iscrizione&codice="+data[0].id+"&idRiferimento="+data[0].idRiferimento+"&data="+data[0].dataOra);


              $("#pdf_specifico").attr("download", data[0].pdf+".pdf");
              $('#pdf_specifico_span').text(data[0].pdf);
              if(data[0].pdf=="no-file"){
                $( "#pdf_specifico" ).hide();
              }else{
                $( "#pdf_specifico" ).show();
              }

              if(data[0].title=="Corso bagnini" || data[0].title=="Corso Bagnini" || data[0].title=="Corso Bagnini Piscina"){
                $("#selezioneMinorenne").show(); //METTERE SHOW
              }else{
                $("#selezioneMinorenne").hide();
                $("#rigaGenitore").hide();
              }

              if(data[0].title=="Patente nautica" || data[0].title=="Patente Nautica"  || data[0].title=="Patente nautica "){
                $("#rigaNauticaPartecipazione").show(); //METTERE SHOW
              }else{
                $("#rigaNauticaPartecipazione").hide();
              }


              $("#exampleModal").modal();
            }
        });

        /*$.ajax({
          url:url+"calendar/getDateSuccessive.php",
          type:"POST",
          dataType: 'json',
          data:{id:arg.event.id},
          success: function(data1) {


            for(let i = 0; i <= data1.length; i++) {
              // alert(data1[i].dataEvento);
              s = new Date(data1[i].start).toLocaleString('it-IT', options);
              oraI = new Date(data1[i].start).getHours();
              minutiI = new Date(data1[i].start).getMinutes();
              oraF = new Date(data1[i].end).getHours();
              minutiF = new Date(data1[i].end).getMinutes();


              $("#successive").append(s+" 0"+oraI+":"+minutiI+" - "+oraF+":"+minutiF+"<br>");
              $("#tmpDateEvento").val($("#tmpDateEvento").val()+s+" "+oraI+":"+minutiI+" - "+oraF+":"+minutiF+";");
              $("#numero").val(data1.length);
              $("#corsiSuccessivi").val($("#corsiSuccessivi").val()+data1[i].id+";");
            }

          }
        });*/

        $('#delete').on('click', function() {
            if(confirm("Sei sicuro di voler cancellare l'evento?")) {
                $.ajax({
                    url:url+"calendar/delete.php",
                    type:"POST",
                    data:{id:arg.event.id},
                });

                //close model
                $("#modalSlideLeft").modal('hide');

                //refresh calendar
                calendar.refetchEvents();

                if(/Android|webOS|iPhone|iPad|iPod|BlackBerry|IEMobile|Opera Mini/i.test(navigator.userAgent)){
                  location.reload();
                }

                // $('body').pgNotification({style:'simple',message:'Evento cancellato correttamente!',type:'success'}).show();
            }
        });

        calendar.refetchEvents();
    }

    });



    calendar.render();

});

Here the link https://corsi.gpserviziarco.it/calendario-corsi/

What i have to do to show the description
Thanks !