Authentication Issue

We were successfully using this module on a site until the client changed their Google password last week and needed to set a new ID and Secret. When we updated that, we're getting this error:

Google\Service\Exception: { "error": { "code": 401, "message": "Request had invalid authentication credentials. Expected OAuth 2 access token, login cookie or other valid authentication credential. See https://developers.google.com/identity/sign-in/web/devconsole-project.", "errors": [ { "message": "Invalid Credentials", "domain": "global", "reason": "authError", "location": "Authorization", "locationType": "header" } ], "status": "UNAUTHENTICATED" } } in Google\Http\REST::decodeHttpResponse() (line 134 of /home/customer/www/organization.org/vendor/google/apiclient/src/Http/REST.php).

We've been trying to configure this module for another site in the same way that we had working on the first site, but we get the same error, which makes us wonder if Google changed how authentication is working and more needs to be configured now.