As per the title really. I have a server running Airsonic (advanced) in Docker and finally pieced together how to get it to interact directly with the Sonos ecosystem. It’s much snappier than simplying “adding a folder” from my NAS or workstation. This should be extremely similar for subsonic, madsonic etc.
Let me know if any questions:
https://www.thesmarthomebook.com/2022/04/04/add-an-airsonic-music-server-to-sonos/