https://karabiner-elements.pqrs.org/
Write rules into a Json file.
The Rules format can be found in:
https://karabiner-elements.pqrs.org/docs/json/
https://github.com/pqrs-org/KE-complex_modifications/tree/master/public/json
Put the configuration file varmilo.json
under the folder: ~/.config/karabiner/assets/complex_modifications/
Open Karabiner-Elements -> Complex modifications -> Add rule