Make example for this keyboard (after setting up your build environment):
make jj40-program
See [build environment setup](https://docs.qmk.fm/build_environment_setup.html) then the [make instructions](https://docs.qmk.fm/make_instructions.html) for more information.
Note that this is a complete replacement for the firmware, so you won't be
using Bootmapper Client to change any keyboard settings, since not all the
USB report options are supported.
In addition you may need the AVR toolchain and `bootloadHID` for flashing: