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.
I've checked your account and I can see that the upload space is empty. It looks like you figured it out how to clear your upload space. You need to delete the actual submission to delete the uploaded files.
Related guide for clearing upload space: How-to-Delete-Form-Submission-Data
Hope that answered your question. If not, please give us more information about the problem your having so we can help you much better. Thank you.