Well, that's not really clean but it worked anyway, and it clearly wasn't 4K.
But if you REALLY want to try, well, it works.
Just download and install Firefox for Android TV/Fire TV here :
Then, go to tv.apple.com, login and click Play. I watched the Morning Show yesterday, could change the subtitles to French, no issue on my Shield TV, not sure how a Mi Box will handle it.
You won't get HDR, 4K, etc, but at least it's playing.
Cheers
Possible to share a screenshot?