@sid, this is more than likely way more than I needed but my end head section looks like this
<script src="dmxAppConnect/dmxCalendar/dmxCalendar.js" defer=""></script>
<link rel="stylesheet" href="https://unpkg.com/@fullcalendar/core@4.4.2/main.min.css" />
<link rel="stylesheet" href="https://unpkg.com/@fullcalendar/core@4.4.2/main.css" />
<link rel="stylesheet" href="https://unpkg.com/@fullcalendar/daygrid@4.4.2/main.css" />
<link rel="stylesheet" href="https://unpkg.com/@fullcalendar/timegrid@4.4.2/main.css" />
<link rel="stylesheet" href="https://unpkg.com/@fullcalendar/timeline@4.4.2/main.css" />
<link rel="stylesheet" href="https://unpkg.com/@fullcalendar/resource-timeline@4.4.2/main.css" />
<script src="https://unpkg.com/@fullcalendar/core@4.4.2/main.min.js"></script>
<script src="https://unpkg.com/@fullcalendar/core@4.4.2/locales-all.min.js"></script>
<script src="https://unpkg.com/@fullcalendar/interaction@4.4.2/main.min.js"></script>
<script src="https://unpkg.com/@fullcalendar/daygrid@4.4.2/main.min.js"></script>
<script src="https://unpkg.com/@fullcalendar/timegrid@4.4.2/main.min.js"></script>
<script src="https://unpkg.com/@fullcalendar/timeline@4.4.2/main.js"></script>
<script src="https://unpkg.com/@fullcalendar/resource-common@4.4.2/main.js"></script>
<script src="https://unpkg.com/@fullcalendar/resource-timeline@4.4.2/main.js"></script>
And now my calendar works perfectly, well in the website it does, in Wappler design view its just a big white hole.