is [this what you’re using](http://www.nuwudmultimedia.com/Documentation.pdf)?
if so, have you read through it? As @bkbillma says, handling money is a delicate matter. You need to be able to understand how APIs work in general, and how to integrate your code with them. If you’re “fairly new to PHP,” it would probably be a good idea to hire someone with some expertise to handle this for you.