You can read about how to access 3rd party services in the article Corvid: How to Access 3rd-Party Services with the Fetch API . You will need to find out from the service provider what their interface is.
Take a look at the Advanced examples , many of them access 3rd party services. A couple of good examples to start with are: Example: Using the Places API from Google Maps services and Example: Send email with the SendGrid REST interface .