FullCalendar v5 - TypeError: $(...).fullCalendar is not a function

I'm using FullCalendar 5.5.1 The problem is that it doesn't display correctly and I keep receiving This Error: TypeError: $(...).fullCalendar is not a function

Here is my code:

$(document).ready(function () { InitializeCalendar(); }); function InitializeCalendar() { try { $('#calendar').fullCalendar({ timezone: false, header: { left: 'prev,next,today', center: 'title', right: 'month,agendaWeek,agendaDay' }, selectable: true, editable: false }); } catch (e) { alert(e); } } 

Here are references:

<script type="text/javascript" src="~/lib/select2/js/select2.full.min.js"></script> <script type="text/javascript" src="//cdn.jsdelivr.net/momentjs/latest/moment.min.js"></script> <script type="text/javascript" src="//cdnjs.cloudflare.com/ajax/libs/qtip2/3.0.3/jquery.qtip.min.js"></script> <script type="text/javascript" src="https://cdn.jsdelivr.net/combine/npm/[email protected]"></script> <script src="https://kendo.cdn.telerik.com/2020.2.513/js/kendo.all.min.js"></script> <script type="text/javascript" src="~/js/notify.min.js"></script> <script src="~/js/script-custom-calendar.js"></script> 

I'm following a tutorial and this worked for him. I don't know why is doesn't work for me. This is the original project: https://github.com/bhrugen/appointmentscheduler