[keycloak-user] Lookup user by federated identity email?

I have a Keycloak instance set up with users who can login via Google, Twitter, etc. I have another separate service (not Keycloak) that also allows login via Google. I’m trying to associate the users from one service to the others. From this other service I can get the email associated with the Google account. Is it possible to locate search for the Keycloak user that has the identical email address in their federated Google identity? I don’t want to look up using the Keycloak specific email as it may be different from the email associated with the federated identity. Ideally I’m looking to do this via the REST api but didn’t see an appropriate endpoint. Thanks, Jeffrey