All of our current Auto-Tune® editions are now supported for use with macOS 10.15 Catalina (provided that your DAW also supports Catalina). This includes Auto-Tune Pro, Auto-Tune Artist, Auto-Tune EFX+, Auto-Tune Access, and Auto-Key.
Avox 4, and the individual plugins that make up the Avox bundle are not yet updated for Catalina support. However, it is possible to install and run them on Catalina.
If you encounter an error message when running the Avox installer on Catalina, please right-click or control-click on the installer and choose "Open." This will give you the option to run the installer.