Recently started administrating a store for a client. His existing CubeCart store is version 3.0.17 (PHP 5.2.17, MySQL 5.5.29-log). Current gateway is Paypal IPN. We are currently not able to accept credit cards since CC only partners with Paypal on Express Checkout from everything I can find. Under the Express Checkout gateway, I am supposed to make sure the API is pointed to this particular URL, but underneath that states "This file does not currently exist."
How do I get the API certificate and will the URL for it to point to work?
Is there any kind of users manual available online for this old version?
Am I just out of luck on such an old version?