can I change authentication provider from google account to be anonymous in firebase authentication?
An user login using Google account as the provider for authentication like the image above. I want to make when the user performs log out, then the provider should change from Google to be anonymous. so I want to make, when user logout, they will be anonymous but with the same userID Bdf2LPraRhbnWhP24eiSN3vTQ5G3
Can I do that?
I need to make it anonymous, because I want that user to still see some contents in my app even when they logout. They need to be in the logged-in state to pass the security rules.
I want to make when the user performs log out, then the provider should change from google to be anonymous.
There is no way you can automatically do that. When the user logs out, the created account still remains and cannot be converted in any way.
Firebase lets you create those anonymous accounts so you can authenticate with Firebase. These are only temporary accounts that can be used to allow users who haven't yet signed up to use your app. It's true that you can convert an anonymous account to a permanent account with Google, but the vice versa is not available.
It's also true that you can log a user out from Google, as well as from Firebase, and delete the Firebase account entirely, but if you try to create another anonymous account, a new UID will be generated. Unfortunately, there is no way to reclaim the old token for the user.
because I want that user to still see some contents in my app even when they logout.
If you want the user to see some content even if they log out, simply display that content also for non-authenticated users. If you want to restrict that only for a particular user, then the user should be authenticated.