hey, I installed paypal website payments pro but I'm having a slight problem. When the customer goes through the transaction proccess and chooses to pay w/ paypal, they get this error:
Authorization Failed
This transaction is invalid. Please return to the recipient's website to complete your transaction using their regular checkout flow.
What could the problem be?
I'm thinking that it might have something to do w/ the API signature but I'm not sure. I do have a signature provided from paypal but I didn't do anything with it. Am I supposed to?
thanks