Use YouTube Videos as Video Backgrounds in Presentation

My website has A LOT of presentation slides, and many of them have mp4 or webm video backgrounds.

Because of this it’s killing the web server and making the site load very slowly (and glitchy).

It was suggested by a professional to host the videos on YouTube as that will take strain off my web server and YouTube is built for video streaming.

But when I put the YouTube URLs in the fields for the background videos, then it doesn’t work.

Is there a way to use YouTube videos as my background videos in the Highend Presentation slides?

My URL is https://great-news.org