$request->SendRequest([postdata])
Sends an HTTP request to the destination server. postdata contains any optional data
to send immediately after the request header; this is generally used for POST or PUT requests.
Your request object must contain the following content header for post
data to be processed. You can add the header with AddHeader:
...
$request->AddHeader("Content-Type: application/x-www-form-urlencoded");
$request->SendRequest("key1=value1&key2=value2&key3=value3");