How to solve the "Notice: Undefined index" error when QT application calls php script

Question

This is my 1 line of PHP code;

<?php
echo $_POST['api']; ?>

This is how my QT application calls the PHP script;

QUrl url("http://*****.com/id.php");
QNetworkRequest request(url);

request.setHeader(QNetworkRequest::ContentTypeHeader, "application/x-www-form-urlencoded");

QUrlQuery params;
params.addQueryItem("api", "test");
networkClients->post(request, params.query().toUtf8());

This is a PHP notification

The code ran seamlessly on my previous hosting provider. After I moved my stuff to hostinger, I am now unable to send data to my application using POST requests ($_POST['api'] returns empty and echo does not output anything). GET requests work fine. I also tested on reqbin and it works fine, but the application doesn't.

Answer 1

QUrlQuery will add parameters to the URL. This means they must be received using the GET method.

<?php
echo $_GET['api']; ?>

However, it is always recommended to check if the value is null.

<?php
if isset ($_GET['api'])
  {echo $_GET['api'];}
else
  {echo 'Not found';}
?>

The POST method can only be used when submitting or posting the form using a form and a button or an input of type button.