iPad Hardware Volume for Sonos

Hello. It’s possible for me to use the iPad volume keys by using hifiberry. But if I stream via Sonos it says fixed volume. The volume control is enabled in the Sonos app and also in the settings in roon. Can anybody help me (and sorry for bad English) tks Alex

Alex in the device settings you can change the settings between digital/fixed/device

Generally Sonos is fully controlled by Roon unless it is a streamer only.

Go into Settings->Audio and try some settings there.
I can’t remember the exact option as I am traveling