extraData indicates additional data in an HTTP request. It varies depending on the HTTP request method.
- If the HTTP request uses a POST or PUT method, this parameter serves as the content of the HTTP request.
- If the HTTP request uses a GET, OPTIONS, DELETE, TRACE, or CONNECT method, this parameter is a supplemental parameter for the HTTP request and will be appended to the URL when the request is sent.
- For a string object, you need to encode the object before passing it to the HTTP request.