Error : Submission failed for URL for Manual and Auto

While looking for something on my site unrelated to this, I noticed the Invalid Api Key message, so I followed the instructions and deactivated it and reactivated it, still not working.

I tried to submit it manually, it still failed. Is this plugin still supported as I noticed someone else is having problems with no response from the developers?

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