Hi, what’s your setup?
I often listen to music through youtube on my phone connected to a bluetooth speaker. I use Newpipe, works very well. Then when I want to save a song or an album, there’s the option for downloading (in newpipe itself) or on android for example Seal (works really well for downloading entire playlists and unselecting some sponsored video’s from the playlist).
The hassle is uploading from the phone to my jellyfin. I’ve used File Browser, bit limited in options.
Then I thought I could use Syncthing to have some folder from my Android phone upload it automatically to my Jellyfin server (pc running dietpi), but it seems Syncthing is now discontinued on Android?
What I was first looking for was my own hosted yt-dlp with a mobile friendly UI, but that seemed quite difficult to get running.
If your phone is android (I think so) and your jellyfin server has a file share (easy to implement anyway) you can use material files (https://f-droid.org/packages/me.zhanghai.android.files/). It has an option to connect via smb.