Need help with my Instant Payment Notification (IPN) PHP Script

[Nerks]

Hello! I have some code below but for some reason it is not getting a VERIFIED or INVALID response.

<?php
   $verify = file_get_contents(urlencode('https://ipnpb.sandbox.paypal.com/cgi-bin/webscr?transaction_subject='.$_POST['transaction_subject'].'&txn_type='.$_POST['txn_type'].'&payment_date='.$_POST['payment_date'].'&last_name='.$_POST['last_name'].'&residence_country='.$_POST['residence_country'].'&pending_reason='.$_POST['pending_reason'].'&item_name='.$_POST['item_name'].'&payment_gross='.$_POST['payment_gross'].'&mc_currency='.$_POST['mc_currency'].'&business='.$_POST['business'].'&payment_type='.$_POST['payment_type'].'&protection_eligibility='.$_POST['protection_eligibility'].'&verify_sign='.$_POST['verify_sign'].'&payer_status='.$_POST['payer_status'].'&test_ipn='.$_POST['test_ipn'].'&payer_email='.$_POST['payer_email'].'&txn_id='.$_POST['txn_id'].'quantity='.$_POST['quantity'].'&receiver_email='.$_POST['receiver_email'].'&first_name='.$_POST['first_name'].'&payer_id='.$_POST['payer_id'].'&item_number='.$_POST['item_number'].'&payment_status='.$_POST['payment_status'].'&mc_gross='.$_POST['mc_gross'].'&custom='.$_POST['custom'].'&charset='.$_POST['charset'].'&notify_version='.$_POST['notify_version'].'&ipn_track_id='.$_POST['ipn_track_id'].''));
   
    
    if($verify == "VERIFIED") {
        echo 'Payment success.';
        $data = "Verified".PHP_EOL;
    $fp = fopen('stats.txt', 'a');
    fwrite($fp, $data);
    }
    else {
        echo 'Payment failed.';
    }
    
    
    foreach($_POST as $name => $value) {
        $put = urlencode($name .'='.$value.'&');
        $data = $put;
$fp = fopen('stats.txt', 'a');
fwrite($fp, $data);
        
    }
    
    
?>

I made it so that it would save the POST data that PayPal gives just to see what is going on.

Thanks for your help 🙂