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.
You may delete the existing Authorize.net payment field from the form and then add the new PayPal payment field to your form. Please make sure that you click on Yes when it is prompted to keep the products.
When you add the new payment field to the form, the products in the existing payment field will be automatically added to the new payment field.
Also, please be noted that when you delete a field from the form and if there are existing submissions for the form, the submission data will be removed for this particular field. If you need to keep the submission data, you may clone the form to your account and then change the payment field to PayPal.
Hope this information helps!