If I understood your problem correctly, you need to listen to Spotify through your HomePod which is on the same local network as your Mac.
This is what I do on macOS. I press on the little megaphone icon (enable it in OS sound preferences) in menu bar and then I can choose my HomePod from the list, without any third party software. I am running Big Sur but in two previous versions I also did the same. Maybe I’m missing something here but I think it should work seamlessly.
This is what I do on macOS. I press on the little megaphone icon (enable it in OS sound preferences) in menu bar and then I can choose my HomePod from the list, without any third party software. I am running Big Sur but in two previous versions I also did the same. Maybe I’m missing something here but I think it should work seamlessly.