In this tutorial--
I learned how to create a payment form. But there's no option on the form builder for recurring billing cycle. Can I add that option for monthly payment somehow? Please help. Thank you!
You do that on the product itself. Under its Cycle bit.
Note: You can only use this if your seamless payment gateway supports recuring Billing.
Yes, I realize I can do that on the product. However, I am creating a payment form with an amount that will be entered by the user. (A monthly donation form.) That's why I am using a web form.
Or if we can create a recurring product with "name your own price" kind of deal, that would work too.
To do that use secure zones. Assign them to a zone and have a monthly fee associated with that. It does not have to be a functional login area but you use the ability to do the reciting from that.