This nodes authenticates to Google services specified in the node settings.
Authentication happens in the configuration window.
After choosing the scopes, one must authenticate using the "Login" button. A pop-up will appear that asks the user to grant access to the selected scopes. If you have already authenticated, the "Login" will test the stored credentials in the selected location.
Access can be revoked at any time by visiting myaccount.google.com/permissions
For details see: developers.google.com/analytics/resources/concepts/gaConceptsAccounts .