Fullcalendar - How to get an update on calendar 1 to trigger a refetchEvents() on calendar 2

Using Fullcalendar.io V6 with Script Tags

I have a page with 2 Fullcalendars. [calendar] and [calendar_list]

<div id="calendar" name="calendar">
<div id="calendar_list" name="calendar_list">

[calendar] is a standard editable calendar with all the standard events to insert, update and delete events with a ajax call to php page. The calendar works just as expected with all the functions performing the updates correctly.

document.addEventListener('DOMContentLoaded', function() {
var calendarEl = document.getElementById('calendar');
var calendar = new FullCalendar.Calendar(calendarEl, {.......});

[calendar_list] is a second calendar next to [calendar]. It is standard 'listYear' calendar and the event source is the same as the main calendar ajax to php page. The purpose of [calendar_list] is to show a list view of all the dates inserted, updated and deleted from the main calendar so the user can see a summary of all the dates selected.

document.addEventListener('DOMContentLoaded', function() {
var calendarEl_list = document.getElementById('calendar_list');
var calendar_list = new FullCalendar.Calendar(calendarEl_list, {......}

Fullcalendar has a function for refetchEvents() which I need to call after and event has been updated in the main calendar and the data has been posted.

Is there a method where I can add some sort of listener to [calendar_list] to trigger the refetchEvents() after [calendar] has updated an event?

Found the solution and it was simple.

I had the var for calendar and calendar_lsit objects declared inside the functions. All I had to do was declare the var outside of the functions so they become global.

var calendar_list;
document.addEventListener('DOMContentLoaded', function() {
var calendarEl_list = document.getElementById('calendar_list');

Once the var is global for calendar_list, I can call the refetch from the ajax success message when the calendar object is updated.

$.ajax({
  url: ....,
  data: {... },
  type: "POST",
  ecnode: true,
  success: function(json) {
   calendar_list.refetchEvents();
},
error: function(xhr, status, error) {
  alert(xhr.responseJSON.message);
}
});