You can check whether a quota supports quota alerts by using the following methods:
Go to the General Quotas page of the Quota Center console. If Create Alarm Rule is displayed in the Actions column of a quota, this quota supports alerts. Otherwise, the quota does not support alerts.
Call the ListProductQuotas API operation on the OpenAPI Developer Portal. If the returned value of the Consumable parameter is true, the related quota supports alerts. Otherwise, the quota does not support alerts.
For more information, see ListProductQuotas.