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.
Do you actually want a user to make a one time donation which he can repeat or you want to allow your user to make a donation just like a subscription?
Please be noted that we do not have such feature where you can accept recurring monthly donations. We only allow a one time donation option.
But you can take advantage of "Sell Subscription" feature of the payment tools to accept recurring amount every month. The following guide should help you: http://www.jotform.com/help/166-How-to-setup-a-recurring-payment-option
Hope this helps.
Do get back to us if you have any questions.