where to put cdn in html code example

Example 1: add cdn html

<!--In-between you head tags put:-->
 <script src="SOURCE URL HERE"></script>
<!--For easy copy/paste:-->
 <script src=""></script>

Example 2: how to start using jQuery CDN

<script
  src="https://code.jquery.com/jquery-3.4.1.js"
  integrity="sha256-WpOohJOqMqqyKL9FccASB9O0KwACQJpFTUBLTYOVvVU="
  crossorigin="anonymous"
></script>