Your link doesn’t work. But I assume you are talking about this label? I looked at the first artist and I found the artist’s music on iTunes. Everything that Apple sells on the iTunes Music Store has been DRM free AAC or ALAC (Apple lossless) since 2009.

https://mountainfever.com/colin-kathleen-ray/

While ALAC is an Apple proprietary format, it is DRM free and can be converted to FLAC using ffmeg. AAC is not an Apple format

ALAC is open source and royalty free since 2011. https://macosforge.github.io/alac/