Ender3 Pro Adding CR Touch

Trying to install the CR Touch on an Ender 3 Pro and not sure what firmware to use and where to get it. It has a 32bit mother board, v4.2.7. This printer was originally and 8-bit unit and the motherboard was upgraded to 32-bit to allow the addition of the CR Touch system. The chip on the board is an STM. Under “About Printer” on the control unit it shows Marlin v1.1.2. Can anyone please point me in the right direction for the firmware so I can get this up and running.