When performing an HTTP POST method callout, what additional information must be provided?

To successfully execute an HTTP POST method callout, the body of the request is a critical component. The body contains the data that is being sent to the server. This is particularly important for POST requests, which typically involve sending data to be created or updated on the server side, such as JSON or XML payloads. By specifying the body, you tell the receiving server what information or data to process.

While headers are also important as they can include metadata, such as content type or authentication tokens, they are not necessarily considered "additional information" specifically unique to POST requests, since they can be relevant for other HTTP methods as well. Query parameters and endpoint type may also be relevant but are not exclusive to the HTTP POST context, as they can apply to various types of HTTP requests. Thus, the body is the defining characteristic of what makes a POST request distinct regarding the data being transmitted.