At the moment service API exposes two endpoints. One of them is for upsert user and the other is for room creation.
The API is explained here : https://github.com/Ericsson/c3-server-sdk.
It’s not possible to recover a password. Changing password is possible if you have the current password.
Pretty much any other user management is not possible, so if you want to have proper user management and perhaps access control you need to integrate with a separate user management system via the service API.