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 assume you're asking how to delete uploaded files seeing that you're way beyond your 100MB Total Upload Space limit.
You need to delete submissions to free up space. Deleting a submission will also delete the associated uploaded file in it.
IMPORTANT: When deleting submissions individually, you will see this warning message (see screenshot below). Please note that deleting submission data is irreversible and will permanently remove it in our servers, including the file uploads on them.
Complete guide: How-to-Delete-Form-Submission-Data