How to play 4k youtube on macbook pro?

Subsequently, how do I watch YouTube in 4K on Mac? YouTube does not support some 4K videos in Safari for Mac. This extension shows a 4K badge in the toolbar if a YouTube video you’re watching offers quality higher than 1080p. Click the toolbar button to open the video in another web browser and enjoy it in full 4K glory.

Likewise, how do I watch 4K on my MacBook Pro? After installing Mac Blu-ray Player Pro, you can go to “Launchpad” and click on its icon to launch the program. The simplified main interface will reduce certain misoperations. Go to File->Open on the menu to open the 4K video you want to watch, and then the software will load and play the movie successfully.

Also the question is, how do I enable 4K in Safari?