In order to use the Betting API, you need to have an Application Key. The Application Key identifies your API client.
You must pass the Application Key with every HTTP request. You do this by setting the HTTP header with the value of the key assigned by Betfair.:
You can create an Application Key for your Betfair account using the /wiki/spaces/OL/pages/1671182 service.
X-Application: "APP_KEY_ASSIGNED"
Please note: the X-Application header is not required when using the /wiki/spaces/OL/pages/1671182 or the /wiki/spaces/OL/pages/1671181 service.