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.
Field on screenshot you provided is Configurable list widget. If you want to set up Configurable list widget on your form, this guide can help you:
In case that you want to sell book I would suggest you to add payment field to your form. Inside of this articles you can find out more about payment tools and how to set payment form:
If I did not understood your question correctly, please explain in more details what you are trying to achieve. Also provide us ID of the form you are working on.
Hope this will help. Let us know if you need further assistance.