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.
What kind of code field you want to add?
If you are trying to add a coupon code field, please refer to this guide: How-To-Add-Coupon-Code-in-the-Payment-Form
If this is not what you need then please get back to us and provide more details about your problem. Thank you.