Android Auth0+Firebase integration

Hello, community! I really hope to clarify the next question.

Currently, I have been searching for opportunity of using Auth0 as authentification provider for Firebase in Android application. The main goal I want to achieve is to get user authenticated in Firebase using token, created by Auth0, and then use Firebase realtime database for application business logic needs.

After investigating the question for a long time among all the tutorials and possible solutions, I came to the conclusion, that there is no possibility of making Auth0 and Firebase work together. As I understood it clearly?

The Delegation API, which would might help me to use firebaseAuth.signInWithCustomToken(credentials.idToken), was fully deprecated for new Auth0 tenatns, API call return 404 error. Configuring Firebase addon dashboard section with all needed information (SDK v3+ tokens) have no effect.

So, the main question is:
Do you provide any alternative of how Auth0 can be used as an auth provider for Firebase? Is it even possible for now?