Create Coupon Code, but not need payment gateway?

I would like to create a coupon code for a product, but jotform is making me define a payment gateway. The way my business is set up I do not want to accept payment at the POS. I would like to create an order form and when someone uses an activate coupon code the total estimate will be reflected. Does anybody know how to set this up?

You can simply use a Purchase Order payment field type: https://www.jotform.com/help/233-How-To-Add-Coupon-Code-in-the-Payment-Form 

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