How to re-auth user if scopes have already been granted

**Describe the bug**
I am asking for permission for Youtube scopes. Youtube has multiple sub accounts under one email.

If I request scopes for a second time, the API sends:

case scopesAlreadyGranted = -8
Indicates the requested scopes have already been granted to the currentUser.
[kGIDSignInErrorCodeScopesAlreadyGranted](https://developers.google.com/identity/sign-in/ios/reference/Enums/GIDSignInErrorCode#/c:@E@GIDSignInErrorCode@kGIDSignInErrorCodeScopesAlreadyGranted)

How do I let a user re-authenticate under a sub email of the YT scope permissions?

**To Reproduce**
Steps to reproduce the behavior:

GIDSignIn.sharedInstance.addScopes(
self.additionalScopes,
presenting: self,
callback: { user, error in
})

**Expected behavior**
Authenticate a sub email under the main email of the Google sign in.

For example: If a user signs out. I would like to re show or re-access the sub emails under the addScopes function.
Essentially, I would like to ask for scopes a second time.

**Screenshots**

**Environment**
- OS: iOS Swift