[אדיר]

return_url	The URL to which the sender’s browser is redirected after approving a payment on paypal.com. Use the pay key to identify the payment as follows: payKey=${payKey}.
cancel_url	The URL to which the sender’s browser is redirected if the sender cancels the approval for a payment on paypal.com. Use the pay key to identify the payment as follows: payKey=${payKey}.