Specifies which Donation Alerts service or endpoint the call is targeting.
api: The request will use the https://www.donationalerts.com/api/v1 base URL, combining it with the url.auth: The request will use the https://www.donationalerts.com/oauth base URL, combining it with the url.custom: The request will not modify or override the url property. The url must be a fully-formed valid URL.
The type of API calls within the Donation Alerts system.