[keychron] set function keys(f1-f12) to work on Ubuntu

According to the cheatsheet comes with the the products, one can press fn + X + L more than 3 secs to switch between function and multimedia keys.

However, this doesn’t work on Ubuntu. No matter how many times (even, odd… -_-) I try, the f1-f12 always perform as multimedia keys.

In order to change them to work as function key we can change the following settings:

ctrl + alt + t # Turn on the terminal

cd /sys/module/hid_apple/parameters
sudo nano ./fnmode

Then change the fnmode’s content from 1 to 0

try fn + X + L (more than 3 secs until the keyboard lights)

yay it works!

source: https://devlog.jwgo.kr/2019/12/13/how-to-fix-fn-key-not-working-between-keychron-and-ubuntu/