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.
When I tried to upgrade my test account, I see that it is redirecting to PayPal page without any issue at my end. Could you try logging to a different browser and see if that works? Please let us know to which plan that you are trying to upgrade so that we can provide you the direct link to upgrade.