YT Music integration runs on top of yt-dlp. If you don't have it installed, it will not work.
It also has some notable issues:
Certain IP ranges (esp. VPNs) are blocked from youtube without a logged in account. In such cases, although playback and search can work (see settings > ytm cookie source) getting the metadata does not properly work, so the miniplayer will be quite impaired.
In general, some people claim to have been IP / Account banned for downloading youtube content,
but it's rare, and most people agree what you might get for abuse is 429 Too Many Requests, which
is a ratelimit.
Don't abuse this and you should be fine, but you are doing this at your own risk!