Switch Sports Golf and automating my Denon AVR

My home audio system goes through a Denon AVR-X1700H as the primary receiver. My house has three pairs of ceiling speakers: one in the living room, one in the dining room, and one in the kitchen. When listening to music I want them all streaming from the same Spotify source, but if I'm playing video games I occasionally want Spotify from just the kitchen/dining room. Let's reverse engineer how the app controls the receicver so I can swap from my watch.