This is the most searching question How to add popup video in html? then you are in right place. Let’s Start

Requirement:

Download Plugin: Download

HTML Markup

<button
class="js-modal-btn" data-video-id="7TUOI23spt0">Open
Video</button>

Now link this css in your html before end of head tag.

<link rel="stylesheet" type="text/css" href="/path/to/modal-video.min.css">

And linking this js file before end of head. Or you can also add this before end of body tag.
Always remember jQuery file should keeps at the top.

<script src="http://code.jquery.com/jquery-2.2.4.min.js"></script>

And then linking this before end of body tag.

<script src="/path/to/modal-video.js"></script>