Sending Dolby Atmos MUSIC to Marantz Receiver

So I downloaded some Apple music (Beatles Abbey Road) in Dolby Atmos. I thought if I used Airplay from my iPhone to send it to my receiver (Marantz Cinema 60), it would play it in Dolby Atmos. But no such luck. Normal stereo. (And Airplay 2 does support Dolby Atmos though, and the Marantz supports Airplay 2).

So how do you send Dolby Atmos music to these receivers that can easily play movies in Dolby Atmos?

I also have Sonos and Heos to stream music -- and can play music from my PC and stream to my Marantz using Sonos and/or Heos. But not sure how to play Dolby Atmos either via Sonos, Heos or Airplay -- does it have to be a file sitting on my PC? (or is there something I'm missing)?