What is the thing with map_firebase_uid_to_username for the key 'FIREBASE_USERNAME_MAPPING_FUNC'

[venqics]

When i try to migrate following as per the instructions, the map_firebase_uid_to_username is undefined variable. How to resolve this?

[samirsd]

agreed, this is poorly explained

[tarikozket]

it's optional, from the documentation:

You can get away with leaving all the settings as default except for FIREBASE_SERVICE_ACCOUNT_KEY, which is obviously required.

it's basically the mapper function for the username field's value which is used while creating users.

you only set it if you would like to have a custom mapper. simply drop it if you don't need a custom mapper.