C# .NET communication with API

//
//    EXAMPLE OF LOGIN REQUEST 
//

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Net;
using System.IO;

namespace ConsoleApplication1
{
    class Program
    {
        static void Main(string[] args)
        {
            // Create a request using a URL that can receive a post. 
            WebRequest request = WebRequest.Create("https://getting-started.postaffiliatepro.com/scripts/server.php");
            // Set the Method property of the request to POST.
            request.Method = "POST";
            // Create POST data and convert it to a byte array.
            //WRITE JSON DATA TO VARIABLE D
            string postData = "D={\"requests\":[{\"C\":\"Pap_Api_AuthService\", \"M\":\"authenticate\", \"fields\":[[\"name\",\"value\"],[\"Id\",\"\"],[\"username\",\"user@example.com\"],[\"password\",\"ab9ce908\"],[\"rememberMe\",\"Y\"],[\"language\",\"en-US\"],[\"roleType\",\"M\"],[\"apiVersion\",\"\"]]}],\"C\":\"Gpf_Rpc_Server\", \"M\":\"run\"}";
            byte[] byteArray = Encoding.UTF8.GetBytes(postData);
            // Set the ContentType property of the WebRequest.
            request.ContentType = "application/x-www-form-urlencoded";
            // Set the ContentLength property of the WebRequest.
            request.ContentLength = byteArray.Length;
            // Get the request stream.
            Stream dataStream = request.GetRequestStream();
            // Write the data to the request stream.
            dataStream.Write(byteArray, 0, byteArray.Length);
            // Close the Stream object.
            dataStream.Close();
            // Get the response.
            WebResponse response = request.GetResponse();
            // Display the status.
//            Console.WriteLine(((HttpWebResponse)response).StatusDescription);
            // Get the stream containing content returned by the server.
            dataStream = response.GetResponseStream();
            // Open the stream using a StreamReader for easy access.
            StreamReader reader = new StreamReader(dataStream);
            // Read the content.
            string responseFromServer = reader.ReadToEnd();
            // Display the content.
            Console.WriteLine(responseFromServer);
            // Clean up the streams.
            reader.Close();
            dataStream.Close();
            response.Close();


        }
    }
}

JsonSerializer serializer = new JsonSerializer();
object result = JsonConvert.DeserializeObject(responseFromServer);

include '../api/PapApi.class.php';
 
$session = new Pap_Api_Session("path_to_your_server.php_file");
$session->setDebug(true); //this will produce output with request/response
if(!$session->login("merchant_name", "merchant_pass")) {
  die('Failed authentication');
}
 
$payoutHistoryrequest = new Pap_Api_PayoutsHistoryGrid($session);
 
$payoutHistoryrequest->sendNow();
 
$historyGrid = $payoutHistoryrequest->getGrid();
$recordset = $historyGrid->getRecordset();
 
//print list of payouts
foreach($recordset as $rec) {
    echo $rec->get('id') . ';' . $rec->get('amount') . ';' . $rec->get('accountid') . ';' . $rec->get('users') .';' . '</br>';
}