There is no public contact channel yet. Saying so seemed better than printing an address that nobody reads.
If something goes wrong
The tool runs entirely in your browser, so the missing contact channel does not stop it working. If something fails, note which tool you were using, what kind of PDF it was and the exact message. That is everything needed to report it once a channel exists.
Download any results you need before pressing “Start over” and selecting the file again. Starting over clears the current edits but does not modify your original file. If the error returns, note the message, file size and page count.