There's a simple way to enable the ClickButtons on a Lenovo X1 Carbon that I already found here: https://askubuntu.com/a/599831/167365
echo "options psmouse proto=imps" > /etc/modprobe.d/psmouse.conf
However, if they're enabled using this way, I can't use two finger scrolling on the touchpad anymore. Is there any way to make both working simultaniously?