You need to adopt this Python script for your needs LibreELEC.tv/frontend-emulationstation.py at libreelec-9.0-rr · 5schatten/LibreELEC.tv · GitHub since Kodi is probably not able to start shell scripts.
Well I have no clue how the internal speakers are attached to the output device so that's probably the reason why it did not work.
Thanks i will try this later tonight.
This great😁
One question: what location do i need to put my python scripts?
I assume /usr/bin is read only.