PHP-соединение с Android на Localhost, ResponseCode 501

Question

Я просто пытаюсь подключить свое Android-приложение к PHP-серверу на моем Localhost. Когда я делаю это, я получаю код ответа 501.

server.php

if(isset($_POST['email']) && isset($_POST['password'])){

    $result = "";
    $email = $_POST['email'];
    $password = $_POST['password'];
    $sql = "SELECT * FROM tbl_user where email='$email' AND password='$password'";
    $result = $conn->query($sql);
    if ($result->num_rows >0) {
            while($row[] = $result->fetch_assoc()) {
                    $tem = $row;
                    $result = "true";
                    $json = json_encode($tem);
                }

            } else {
                $result="false";
                echo "No Results Found.";   
        }
                echo $result;
                echo $json;
}

My MainActivity

   @Override
    protected String doInBackground(String... params) {
         'i am entering the ip of my pc'
            url = new URL("http://192.168.0.1/test/server.php?");
            conn = (HttpURLConnection)url.openConnection();
            conn.setRequestMethod("POST");


            // Append parameters to URL using Uri.Builder and the 
               String query = builder.build().getEncodedQuery();
            // Open connection for sending data

      // my response_code value is 501
       int response_code = conn.getResponseCode();

  - when i run the code, my response_code value is 501
  - i get IOException