Unable to allow Additional Product Options on Payment Integration

I'm having a another issue now where I cannot have someone order a small and a large product. It seems there is a checkbox for on or off, other forms allow you to pick a large and add, choose and additional medium and add, then decide you want a different product and add 2 or 3 of different sizes. This form isn't allowing me, it's either on or off.

Based on your above issue it seems to me that you are trying to add small and large options to your product and allow more to be added to it.

 

These 2 guides below should help you along further with your payment form:

#1 - https://www.jotform.com/help/165-Setting-Up-Your-First-Order-Form

#2 - https://www.jotform.com/help/225-How-to-Add-Options-to-Payment-Forms