What is JotForm?
JotForm is a free online form builder which helps you create online forms without writing a single line of code. No sign-up required.
At JotForm, we want to make sure that you’re getting the online form builder help that you need. Our friendly customer support team is available 24/7.
We believe that if one user has a question, there could be more users who may have the same question. This is why many of our support forum threads are public and available to be searched and viewed. If you’d like help immediately, feel free to search for a similar question, or submit your question or concern.
I assume you are referring to a sub product, is that right? You can check this guide: http://www.jotform.com/help/264-Create-Sub-Products-Based-on-a-Product-Option.
Or if you just want to add or edit your product list, you just need to open the payment wizard by clicking the wizard icon.
Do let us know if I misunderstood your question.