HTTP APIs
To make a call to an HTTP API, follow the broad procedures below:
1.Click the 
toolbar button. Alternatively, go to the Insert menu and select Web Service Function. This causes the Web Service Call Settings dialog to appear (screenshot below).
2.In the Service Definition section, select the relevant service definition type. Depending on the option you select, different sets of settings will be displayed. For details, see the following topics:
3.Define the settings of the web service call.
4.Click OK. The web service call will appear as a component in the mapping.
Examples
For step-by-step examples of how to call an HTTP API, see:
•Example: Mapping Data from an RSS Feed
•Example: OAuth 2.0 Authorization