How do I clear up upload space?

I am currently over quota in my upload space. How do I clear that up to reactivate my account? Also, is the upload space the files(images) that I uploaded, or files that my clients submitted on the form? Please clarify. Thank you.

The upload space in your account is affected by the files that were submitted through your form, not the files you use for your images.

To free space up, simply delete the submissions which contains the link to the files. Make sure you download your submission data first or that you have integrated the form with a 3rd party service such as Google Drive, Google Spreadsheet or Dropbox.

To do this, find and Click "Integrations" button

Click "Document Sharing" tab and Choose  any of those.