PHP Redirect with POST data

Question

I did some research on this topic, and there are some experts who have said that it is not possible, so I would like to ask for an alternative solution.

My situation

Answer 1

You can use sessions to save $_POST data, then retrieve that data and set it to $_POST on the subsequent request.

User submits request to /dirty-submission-url.php
Do:

if (session_status()!==PHP_SESSION_ACTIVE)session_start();
     $_SESSION['POST'] = $_POST;
}
header("Location: /clean-url");
exit;

Then the browser redirects to and requests /clean-submission-url from your server. You will have some internal routing to figure out what to do with this.
At the beginning of the request, you will do:

if (session_status()!==PHP_SESSION_ACTIVE)session_start();
if (isset($_SESSION['POST'])){
    $_POST = $_SESSION['POST'];
    unset($_SESSION['POST']);
}

Now, through the rest of your request, you can access $_POST as you could upon the first request.