You are right, EmbeddedService[ ] doesn't currently work with YouTube videos, and we are working to fix this.
That is why I suggest using EmbeddedHTML[ ] instead, by providing the Share -> Embed script from the YouTube video webpage. Try this

EmbeddedHTML["<iframe width=\"560\" height=\"315\" \
src=\"https://www.youtube.com/embed/mBpGUPCXQhk\" title=\"YouTube \
video player\" frameborder=\"0\" allow=\"accelerometer; autoplay; \
clipboard-write; encrypted-media; gyroscope; picture-in-picture\" \
allowfullscreen></iframe>"]

Thank you! I tried this before and it didn't work in Safari on my mac. Knowing that my coding was correct... I tried this in Chrome on my mac. It works!

It looks like there is a problem in Safari. The closest I get to work can be seen in the quicktime movie I linked you to below. The file is in .mov format. As you can see... I start to get a video but the video flickers on and off repeatedly and never plays. I completely reset safari and even tried it on another mac. Both have the same problem. Is there a fix for this? Some setting that needs to be changed in Safari perhaps?

Thank you so much for confirming my coding. I thought I was missing something.

Problem in Safari

I sent Wolfram the information too. It looks like they have sent this information to their developers for a fix. Until then, I recommend using Chrome. Hope this helps. And thanks again Pieter!

Hello Michael McCain,

Thank you for contacting Wolfram Technical Support.

I see from your Wolfram Community post ( http://community.wolfram.com/groups/-/m/t/410913?p_p_auth=f1Eb8bFV ) that there is an issue with the code only when using Mathematica Online on the Safari web browser. It does seem that video embedding is not behaving properly in this case and I have forwarded an incident report to our developers with the information you provided.

We are always interested in improving Wolfram products and services and I want to thank you for bringing this issue to our attention.

Please don't hesitate to contact us, if you run into any other behavior problems.

Regards, Abhinav Verma Wolfram Technology Engineer Wolfram Research, Inc.

Hi all, It seems it doesn't work anymore, at least not exactly the same way.... Would need of refreshing the procédure. Thanks

Thanks for that quick answer: If I want to embed a Vimeo video, it works fine, but not with YouTube. Here is an example coming from the Wolfram Documentation that doesn't workif I try to use it :

EmbeddedService[{"YouTube", "mBpGUPCXQhk"}]

If you write

EmbeddedHTML["

then paste the embedding script, Mathematica will ask you in a pop-up to deal with this automatically, just click yes and it will be pasted in the correct format. Then add

"]