What is the proper way to set up a Paypal payment with a PHP cart? I'm not sure if Paypal has some specific API you can use with PHP to help with the checkout process, but I've been struggling for a while to try and figure out how to set up a small cart with Paypal.
Paypal works with any HTML and any server side language and so there is no issue with Paypal and PHP integration. Try the documents with your Paypal sandbox account and it pretty much explains everything.