I don't believe there is any way to stream Apple Music in hi-res to your stereo system. Air Play is limited to 16/44. I don't know of any third-party streamers that handle Apple Music (well, Sonos has Apple Music, but not hi-res).
I think your only option is to tether an iPad or iPhone via USB to a DAC and then into your stereo. Not an elegant solution. (I guess you could tether a computer as well).
It's a shame Apple won't play with any third-party streamers. I have Apple Music included in my cell phone plan, so I have tried it via my headphone rig. I prefer the way that Apple saves and organizes your favorites compared to how Tidal and Qobuz do it.
