forgot to include the epay callback url in the form

shop/templates/epay_form.html

@@ -15,6 +15,7 @@
         'orderid': "{{ order_id }}",
         'accepturl': "{{ accept_url }}",
         'cancelurl': "{{ cancel_url }}",
+        'callbackurl': "{{ callback_url }}",
         'hash': "{{ epay_hash }}",
     });
 </script>
@@ -26,3 +27,4 @@
 </script>
 {% endblock shop_content %}
 
+