How to buy music from Apple Music?

Hello,

I downloaded on my iMac an album of a musician, from Apple Music, and I don't know how do buy it, to be able to do a CD?

Is it possible to downloaded definitively from Apple Music, an album by buying it, on the HD of my iMac?

Currently this album is on my Music Library, as Apple Music file, but as it is protected ( and I understanding that kind of rule ), I simply can eared it, not doing a CD for my car.

Thank you for your help.