fix: use SimpleCheckout hash, if exists

bin/frontend/controls/CouponCodeInput.js

@@ -136,6 +136,11 @@ define('package/quiqqer/coupons/bin/frontend/controls/CouponCodeInput', [
 
             if (SimpleCheckoutNode) {
                 const SimpleCheckout = QUI.Controls.getById(SimpleCheckoutNode.get('data-quiid'));
+                let orderHash = window.location.hash.substring(1);
+
+                if (!orderHash || orderHash === '') {
+                    orderHash = SimpleCheckout.getAttribute('orderHash');
+                }
 
                 QUIAjax.get('package_quiqqer_order-simple-checkout_ajax_frontend_getOrder', (response) => {
                     CouponCodes.addCouponCodeToBasket(code, response.order.uuid).then(() => {
@@ -158,7 +163,7 @@ define('package/quiqqer/coupons/bin/frontend/controls/CouponCodeInput', [
                     });
                 }, {
                     'package': 'quiqqer/order-simple-checkout',
-                    orderHash: window.location.hash.substring(1)
+                    orderHash: orderHash
                 });
 
                 return;