How to generate a Dolby Atmos Apple compatible file

Hi

I am not new to Nuendo or music production (30+ years in the business) however I am new to uploading to Apple and specially getting an immersive track loaded up there.
I mixed some music in Quad (that is my setup so that is my limitation) and it sounds great. Now, can this (via Dolby render or whatever) be translated into an Atmos compatible file for Apple Music?
I realise that Dolby Atmos is generally many more channels that four - however I also understand that one of the points of Dolby Atmos is that it will adapt any source to the outputs offered to it?
Anyways - can this be done? I do also have access to a sub channel potentially. So a 4.1 mix is possible.
What’s the process? Any good resources to learn this?
Thanks
(did someone say dobly?)