How to create a Unibeast usb install Stick with Catalina when it isn't available in the app store ?

On my Hackingtosh runs e.l.capitan.
I want to install Cataline an my Hackingtosh with an unibeast usb stick.
But Cataline is not available in the Mac os app store
Where i can download Osx Cataline.

Author: Strictland