In order to manage your uploads, you should create an account with Uploadfiles.
(all account types can manage uploads, so a free account is fine)

If you have already uploaded files, you can still manage those uploads by registering on the same device, once you reach your dashboard you should see all previous uploads:

If you are unable to register on the same device, or cannot see your previous uploads, you can email us or use our chat widget to request a file deletion.