Do you need a paying account for it to work? I didn’t realise all these piracy apps existed for music on Linux. They completely passed me by!
I think you do need an account (which could be trials) because you have to use an ARL or your credentials to login to Deemix with.
I personally pay for a Deezer family plan and just use offline play mainly for my car.
From what I remember MP3DownloadNet uses the Deezer API to download MP3s and FLAC. I used to collect music with this site before it all the ads but it seems like it’s still working.