Troubles to play AppleTV output on Sonos speakers through triggered by an event

Hello,

In the meantime, I could realize much automation with the help of ChatPPT or MS Copilot, but with this automation, I just don’t reach my goal no matter how long I try.

Automation: The trigger is to switch on a Samsung TV with a connected AppleTV. I detect the switch on through my AVM router and the AppleTV integration.
Action: I have various Airplay and Sonos speakers in the house, and as soon as the TV switches on, two Sonos ceiling speakers (via Sonos Amps) and two HomePods should ungroup from their current jobs and play the TV sound from the AppleTV.
When switching off, the group is dissolved again (this part is simple)

I can’t get the Apple TV audio output to the speakers. This may be simple, but everything is failing now.

Could someone who has experience with this or has any ideas on how to achieve this setup, please share her / his insights?

Thanks for any help