Hate to be the bearer of bad news but all SDK’s are depreciated with no migration. See here
That includes functions, wire protocols, data access permissions and storing/access Atlas data.
Essentially anything related to Realm / Atlas is dead.
You’ll have to re-tool your app for another platform.
At there moment there are dozens/hundreds of us developers searching for alternate solutions but from what I gather none are “ideal” although several companies are stepping up to provide some possible solutions.
We are Swift, macOS based for our apps, and we’re not having much luck with any kind of “smooth” transition. It’s going to be a total re-write for us.