How do I add products?

How do I add a product to JotForm so that it can be selected with a payment amount? 

If I'm understanding your concern correctly, I believe you are trying to set up a payment field on your form.

If that is the case, I suggest that you check the information on how you can do that in this guide — Mastering-Payment-Form-Integrations-with-JotForm

However, if you just need your respondents to give you the information of their order but not collect their payments through your form, then you can follow the instructions in this guide instead — How-to-Create-Payment-Form-with-Purchase-Order

I hope this helps. If you have other questions or concerns, please do not hesitate to let us know.