问在PayPal (onApprove)中完成采购时发送数据

EN

 <script>
                                // Render the PayPal button into #paypal-button-container
                                function loadAsync(url, callback) {
                            var s = document.createElement('script');
                            s.setAttribute('src', url); s.onload = callback;
                            document.head.insertBefore(s, document.head.firstElementChild);
                            }


                            // Usage -- callback is inlined here, but could be a named function
                            loadAsync('https://www.paypal.com/sdk/js?client-id=test&currency=USD&disable-funding=card', function() {
                            paypal.Buttons({
                                // Set up the transaction
                                createOrder: function(data, actions) {
                                    return actions.order.create({
                                        purchase_units: [{
                                            amount: {
                                                value: <?echo $cart->getCartTotal(true)?>
                                             
                                            }
                                        }]
                                    });
                                },
                                // Finalize the transaction
                                      onApprove: function(data, actions) {
            // show loader on screen whilst wating to redirect
            $('.checkout-loader').addClass('active');
            
            // excute php script
            var EXECUTE_URL = 'https://example.com/TESTS.php?success='+success;
            // Authorize the transaction
            actions.order.capture().then(function(details) {
                // Call your server to validate and capture the transaction
                return fetch(EXECUTE_URL, {
                    method: 'post',
                    headers: {
                        'content-type': 'application/json'
                    },
                    body: JSON.stringify({
                        orderID     : data.orderID,
                        success : "okaysuc"
                    })
                }).then(function(response){
                    // redirect to the completed page if paid
                    window.location.href = '/success/' + data.orderID;
                });
            });
        }
    }).render('#paypal-button-container');
                            });
                            </script>

<?php  
$retour = $_POST['success']; //I have tried json_decode() also, didnt work....
$db->query("INSERT INTO mydbname(order_id) VALUES ('$retour')");   //empty data is added to databse  
$cart = new Cart();
if($retour == 'okaysuc'){
//my code goes here.. But not works because data is empty. it is not sent. 
}
?>