How to understand that plugin is working

Afraid I can’t open the site (I get a SSL connection error?), but the easiest way is checking the HTML source code and looking for the word lyte in it. If you find it a couple of times, it works ??

We were setting CDN so website was not working for some time. Can you look it now?

no, afraid those are normal (slow) YouTube embeds :-/ did you flush all page caches you (and your host) might have?

Yes, all caches are clean. What should I do for the plugin to work?

well, it _should_ work out of the box, so if it does not it’s likely a conflict with the plugin (or theme) you use to add YT videos? :-/

How should it look when plugin is working? Can you please provide a screenshot of some demo or another web-site where it’s working

sure, see https://blog.futtta.be/2023/08/10/about-to-see-wilco-live/ for example.