Paste a SoundCloud link. If the artist released the track under Creative Commons
or into the public domain, it comes back as a tagged m4a you can drop straight into your library.
Getting it into your own library
Download the m4a to your phone or Mac.
iPhone: open Files, tap the file, Share, then Music.
Mac: drag the file into the Music app.
Your account is yours. This tool never asks for an Apple ID, an iCloud password,
or any login, and it could not use one if you offered.