JSFiddle - React, Tailwind, and code Playground

HTML

<a id="test" rel="wp-video-lightbox" href="https://www.youtube.com/watch?v=xxxxxxx&amp;width=640&amp;height=480" title="">Watch Movie</a>

JavaScript

$(document).ready(function(){
    var rel = $('a[rel="wp-video-lightbox"]');
        rel[0].click();
});