When a user signs in with a social provider like Google or LinkedIn, retrieve their email address from the provider’s response. Check if the email address is already associated with an existing user in your system. If it is, you can link the new social provider account to the existing user account using the Account Linking feature.
To link the accounts, use the Auth0 Management API’s POST /api/v2/users/{user_id}/identities endpoint, passing the user_id of the existing user and the new social provider’s access token or ID token. This will associate the new social provider account with the existing user account.