[Blind-sysadmins] Trying the Code-Crafters Ability FTP Server

I'm having an accessibility problem. How is the SSL certificate dialog activated? On the screen there's a combo box presumably to select which key pair you want to use, and if you click there with the mouse pointer, it turns into a list box. The help says a dialog is supposed to open, giving you the option to import or create a certificate, but try as I might, unless there's some secret key combination, I can't figure out how to open that dialog. Anyone can help, greatly papreciated. TIA.