You mean the radial menu with Warn, Alert, Special, Death and Pain voice lines? You can see it when you play as Special Infected and press Orders menu (button Z by default).

If you see this menu but nothing happens when you select lines, it means you're playing on a server which allows add-on in Versus (or other competitive modes), but the server itself doesn't have my vocalizer installed on it, so those lines won't work then.

You can locally host Versus game and everything will work (of course if there isn't any add-ons conflict).