The top answer no longer works, but this reddit answer functions as of May 2021.
You can copy the other person's playlist to the new playlist by taking
the url of the other person's playlist, swapping out the www for music
(www.youtube.com to music.youtube.com ) which will give you the
youtube music version of the playlist. from there you can click on the
To link your website with your YouTube channel, the first criteria is to be part of YouTube Partner Program (YPP). You need to have at least 1,000 subscribers and more than 4,000 valid public watch hours in the last 12 months to be part of YPP.
If you are already part of YPP, you can associate your site with your YouTube account:
Sign in to YouTube Studio.
Right Click on Video
Copy Debug info.
Paste it in a Text editor, Like Notepad.
Tap Ctrl+F and search for "VideoID" or "AdDocID" (Not Lower Case Sensitive).
you will find Video ID there (Lower Case Sensitive)
(ID in form of
, add it to ...
I made a Google Apps Script that will do this exact thing. If interested you can check it out here: Automatically add new YouTube videos to Watch Later list.
Basically, the script will go through the list of YouTube channels you give and whenever a new video gets uploaded by any of the channels it will add it to your desired playlist. You can change the ...