To program your Code 3 Z3 siren, you will primarily use the Matrix Configurator Software available directly from the Code 3 website
If the 2021 software is no longer available, consider these options:
Official Matrix Configurator: Download the latest version directly from the Code 3 ESG Software Page.
Hardware Setup: Ensure the siren is powered correctly (Ground and Power connected) and that the ignition wire is not hooked to power while attempting to connect via USB. Configuration Procedure Code 3 Z3 Matrix software - missing USB/CD | eLightbars
The question burning up forums in 2021 was: Where can I download the Code 3 Z3 software this year?