Returns the instance of the Realtime Database SDK that is associated with the provided FirebaseApp. Initializes a new instance with default settings if no instance exists or if the existing instance uses a custom database URL.
Optional
The FirebaseApp instance that the returned Realtime Database instance is associated with.
Returns the instance of the Realtime Database SDK that is associated with the provided FirebaseApp. Initializes a new instance with default settings if no instance exists or if the existing instance uses a custom database URL.