it's working now, great!
hovewer there are some problems,
some remote control buttons are not working as expected, volume controls are ignored, back button ignored when you're on main screen, also there's no way to close addon... don't know if possible to map RC buttons to add-on, keymap editor addon from kodi doesn't help here
As you know Libreelec is an Small os for Kodi. Remote configuration only works with kodi. If we close kodi and run any program like Chrome, remote controller may don't work. You can play lirc / irw to reconfigure keyboard for work globally. I have nothing to do with your remote. You can use cheap wireless mouse / keypad like