I’ve been using Deemix for several years, but it’s not maintained anymore and it finally stopped working :<
But the way it worked was you paid for a deezer.com subscription and gave the login arl token to the deemix app. Then the app could download the music files using your account.
Is there anything like that these days?
You can use yt-dlp on non-YouTube sites.
And I know there are ways to enter credentials and stuff so it might actually work for OP. Not sure though.
It’s such a wonderful piece of software.