Very easily said but extremely difficult to do. As has been said many times before, Apple doesn’t freely publish an API that allows third parties to do that and even in the rare cases where they have, such as for Sonos or Tesla, only lossy AAC support is provided.
If you want full hi res Apple Music support, you either need to use a wired solution, or invest in a much more expensive streamer such as an Eversolo DMP-A6 or FiiO which use the native Apple Music app on a customised version of android with bespoke audio drivers.
If it were possible for WiiM to do it, they’d have done it already.