Mandate SSO (deactivate passwords) option at the user level

My company uses Google's SSO to login, however there is also a username password option. If someone sets their password, they can login with either Google OR their username and password. I would like a setting to mandate that they need to login with Google rather than a username and password (deactivating login through password) at the user level.
The reason I need it at the user level is because functional users exist. The security solution there is setting up API tokens for functional users, and that's a whole different thing related to APIs that I don't want to conflate here.