How can I pull the Tinymce editor to the update modal in the format I want?

How can I get the formatted version of the update modal? I get an error:

tinymce.js:13767 Uncaught TypeError: Cannot create property ‘format’ on string ‘<h2 style=”box-sizing: border-box;

var secilendeger;

function textDuzenle(pid) {
  update = true;
  $('#exampleModalSizeLg').modal('show');
  secilendeger = $('#kt_datatable').DataTable().data().filter(x => x.Id == pid)[0];
  //$('#p_Ack').val(secilendeger.Desc);
  tinymce.get("p_Ack").getContent(secilendeger.Desc);
}