How to add PayPal Pro Direct Payments to your website using php.
Published February 23, 2013 at 11:57 AM
For the code for the form and processor check out http://codebabble.com/web-development/integrate-paypal#comment-6183 .
It's super simple.
For your API credentials login to PayPal > Profile > My Selling tools > Selling Online (section of page) > API access (click update) > Choose option 2 (and click "View API Signature") > There you are with your API Signature.