Service accounts cannot invite attendees without Domain-Wide Delegation of Authority
I already followed these steps and no changes applied.
- From your Google Workspace domain’s Admin console, go to Main menu menu > Security > Access and data control > API Controls.
- In the Domain wide delegation pane, select Manage Domain Wide Delegation.
- Click Add new.
- In the Client ID field, enter the service account’s Client ID. You can find your service account’s client ID in the Service accounts page.
- In the OAuth scopes (comma-delimited) field, enter the list of scopes that your application should be granted access to. For example, if your application needs domain-wide full access to the Google Drive API and the Google Calendar API, enter: https://www.googleapis.com/auth/drive, https://www.googleapis.com/auth/calendar.
- Click Authorize.