Set events inside viewrender callback

So i have this calender. You can see below. When the page is first loaded i populate the ‘events’ propertie of the calender which works fine. What i am having problem with is updateing the ‘events’ propertie inside the ‘viewrender’ eventcallback. Is that possible.

Iam using fullcalender version 3.9.

I tried inside the viewrender to set …. this.setevents. But it dont seem to work

    $("#request_calender").fullCalendar({
    eventOverlap: true,
    selectable: true,
    views: {
        listDay: {
            buttonText: 'Custom View',
        },
        agendaWeek: {
            columnFormat: 'ddd D/M'
        }
    },
    slotLabelFormat: 'H:mm',
    customButtons: {
        toggleWeekends: {
            text: 'show weekends',
            click: function() {
                toggleWeekends();
            },
        }
    },
    header: {
        left: "prev,next today toggleWeekends unBooked",
        center: "title",
        right: "agendaDay,agendaWeek,month,listWeek"
    },
    weekends: false,
    weekNumbers: true,
    defaultView: 'agendaWeek',
    select: function(startDate, endDate) {
        start_date = startDate.format();
        end_date = endDate.format();
        new_request(start_date, end_date);
    },
    events: calender_array,
    timeFormat: 'H(:mm)',
    eventRender: function(e, t) {
      //some code here
    },
    eventClick: function(event, jsEvent, view) {
        console.log("event:", event);
        request_id = event['request_id'];
        request_details(request_id);
    },
    viewRender: function(view, element) {
        //HERE I WANT TO GET DATA VIA A API AND PUSH TO EVENTS
        if (view.name == 'listDay') {
            showCustomView();
        }
    }
});