Apple removed Digital Rights Management (DRM) restrictions, allowing users to play their purchased music on any compatible device.
If you have high-quality files (like WAV or FLAC) and want to convert them to the standard for space-saving on your phone, you can do it directly in the Apple Music/iTunes app : itunes plus aac m4a sites top
You're looking for websites that offer iTunes Plus AAC M4A files. Here are some top sites that provide access to music in this format: itunes plus aac m4a sites top