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.
To delete the uploaded files, you'll need to delete the related submissions from your account. As I check your account, I don't see any occupied space with the files in your account. Please be noted that the deleted submissions cannot be recovered in any way. Please make sure that you are having a backup of your submissions/files before you delete the submissions. You may consider integrating Google Drive or DropBox for backup purposes.
Hope this information helps.