I was looking for a way to copy my "likes" in YouTube music over to a playlist, in the hopes of stopping YTM from losing songs I have liked. I found this script, but it didn't work for me, so I had to look for other solutions. In the end, this is what worked for me.
It's a small Python script that uses the YTMusic python library to copy tracks from my likes to a new playlist. I will try to outline the steps to run the script, but this will assume some familiarity with Python.
Hopefully this will work for others as well!
from ytmusicapi import YTMusic
yt = YTMusic('oauth.json')