libinput kcm touchpad configuration?
 

in Gentoo + KDE + libinput
touchpad setting is missing in KDE Setting > Input Devices

I googled and found that KDE Touchpad Configuration now supports libinput.
https://www.phoronix.com/scan.php?pa...-Configuration

I have been googling weeks, but no solution.
Please advice. Thanks in advance.

Don't use Gentoo, but I've never gotten it to work unless you're using Wayland, not Xorg. With libinput + Xorg, I just revert to synaptics because libinput simply doesn't work properly with any laptop I've ever tried it on.