Lutron audio pico & Sonos: can I sync volume?

I’ve added the Lutron Caséta integration, because I’m looking for a way to sync the volume with another speaker, when I press volume UP/DOWN on the Lutron Audio Pico. What’s really annoying about the Audio Pico, is that the volume only controls ONE speaker, even though it’s in a group ?!

Can I do something with HA to sync the volume to another speaker

What would be the best way to do this ?

The Lutron integration has 2 entities for volume

bathroom_audio_pico_raise
bathroom_audio_pico_lower