Related:
Firebase initializeApp(config); fun
Does an app need to call intializeApp() for gmail login?
The docs mention that, "yes", a config object needs to be passed to initializeApp(), yet, functionally, login and db reads can be done outside the firebase sdk (user login).
Is there any workaround where the config is not used (I don't have access to it at)?
Calling initializeApp tells the SDK what Firebase project to connect to on the servers. So: yes, you need to call initializeApp before you can call the SDK method to sign in with email/password.