PayU payment module for Isotope eCommerce

Payment module for PayU (www.payu.pl). Set the POS configuration in PayU panel as follows:

Error return url: http://www.domain.com/checkout/step/failed.html 

Success return url: http://www.domain.com/checkout/step/complete.html?uid=%orderId%

Reports url: http://www.domain.com/system/modules/isotope/postsale.php?id=5&mod=pay (where 5 is a payment method ID)