You need to download the YouTube App from Microsoft to be able to play.
If you are on a site with a video linked to YouTube and clicked to that video and the app was not installed in your device the browser should redirect you to Marketplace.
Did this solve your problem?
Sorry this didn't help.
Great! Thanks for marking this as the answer.
How satisfied are you with this reply?
Thanks for your feedback, it helps us improve the site.
How satisfied are you with this response?
Thanks for your feedback.