Mongodb Immegration from Atlas to Realm

I'm looking for some advice & consultation on a MongoDB migration we're doing to serverless MongoDB with Atlas/Realm.

At the moment we're trying to understand serverless functions inside of Atlas for CRUD and User Auth/Setup/Delete/etc

Next we'll be looking at database migration and other more complicated functions.

Please apply if you have specific experience working with https://realm.mongodb.com

Thanks :)