Can I use an old Apple TV for audio airplay using Apple Music only?

So I’m hoping there is an easy answer to my question. I’m looking for an inexpensive way to bring airplay to a home theater receiver and noticed that older Apple TV’s are cheaper than airport expresses in general on eBay. They’re also black like the rest of my audio components.

Anyway, I have an Ethernet cable that I can connect to the Apple TV near the receiver and the (older) receiver has optical and hdmi inputs. So in my head it should work but since I don’t really know for sure, I’m here to ask.

If this would work, then which generation would be best? Does 1st gen work? Second? Third? Are any capable of airplay 2? Is the Apple tv always on so when I switched to the receiver input it would work without needing to wake up the tv with a remote? If so then I shouldn’t need the remote at all (cheaper that way). Finally, some hardware is so old that one can’t even set them up any more. Want to make sure that doesn’t happen.

Thanks.