[upg-edit] invalid request

I have set up [upg-list] on this page, where the public gallery only shows images uploaded by the owner of this profile page.

I need to allow the user to edit (remove) images he previously uploaded. If I’m getting this right, I added [upg-edit] to the code. However, it is shown as “Invalid request” on the page (bottom of the page).

Thanks in advance for helping!

The page I need help with: [log in to see the link]