Add specific Google permissions to different Auth0 users


Our application uses Auth0 authentication which currently supports Google OAuth and email/password. In the future we will also add Apple and maybe other supported providers.
We are working on a feature that allows users to export their text output to Google Docs. To allow this we need to request permission for “”.
It’s easy if the users create accounts with Google OAuth, but we want to allow also users that have email/password accounts to export to Google Docs so we would like to request only the “” permission for them.
What would the best solution in this case be?
Should we create an additional Google account for them and link the accounts together or is there another way of adding a Google OAuth scope to an account that was created using a non-Google OAuth?