JotForm is a free online form builder which helps you create online forms without writing a single line of code. No sign-up required.
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.
It is not currently possible to limit the quantityof products that can be purchased, with payment tool wizard.
A workaround is to use one of our inventory widgets , Form calculation widget and donation option of payment field. You can perform calculation inside of your form and pass calculation to payment field.
Inside of this guide you can find out how to perform calculation in the form:
Here is a link to our inventory widgets: