If single sign-on (SSO) has been enabled for your StorageGRID system, you cannot use the standard Authenticate API requests to sign in to and sign out of the Grid Management API or the Tenant Management API.
Signing in to the API if single sign-on is enabled
If single sign-on (SSO) has been enabled, you must issue a series of API requests to obtain an authentication token from AD FS that is valid for the Grid Management API or the Tenant Management API.