Available Endpoints

Method	Endpoint	Description
GET	`/api/2.0/letters/`	List Letters
GET	`/api/2.0/letters/{id}/`	Retrieve Letter
POST	`/api/2.0/letters/`	Create Letter
PATCH	`/api/2.0/letters/{id}/`	Partially Update Letter
PUT	`/api/2.0/letters/{id}/`	Update Letter
GET	`/api/2.0/referral_orders/`	List Referral Orders
GET	`/api/2.0/referral_orders/{id}/`	Retrieve Referral Order
POST	`/api/2.0/referral_orders/`	Create Referral Order
PATCH	`/api/2.0/referral_orders/{id}/`	Partially Update Referral Order
PUT	`/api/2.0/referral_orders/{id}/`	Update Referral Order