In Xubuntu I like to have a 2 finger tap as the middle button, and a 3 finger tap as right click. This is mostly to make opening and closing tabs in Firefox easier. By default on most operating systems it’s the other way round. I used to use synclient to do this but that stopped working in either 24.04 or maybe even 22.04. As usual, the Arch Wiki has the answer.
You create a file at
/etc/X11/xorg.conf.d/30-touchpad.conf
and then paste the following into it:
Section "InputClass"
Identifier "touchpad"
Driver "libinput"
MatchIsTouchpad "on"
Option "Tapping" "on"
Option "TappingButtonMap" "lmr"
EndSection
A quick reboot later and the 2 and 3 finger taps are swapped.