Server Key: Mid-server-VWcHi6YMhvY0l1IBlHgzm1K7
Authorization Header: Basic TWlkLXNlcnZlci1WV2NIaTZZTWh2WTBsMUlCbEhnem0xSzc6

Direct cURL Test:
HTTP Code: 401
Response: {"status_code":"401","status_message":"Unknown Merchant server_key/id","id":"f6d255bc-dd8a-4728-98bd-ae48fe726702"}