Hello Peter Perros.

I think that you should create the configuration file /etc/X11/Xsession.d/15x11-synaptics using your favourite text editor. The content of that file could be
Code:
#
synclient TapButton1=1 TapButton2=3 TapButton3=2 HorizEdgeScroll=1
The file should end with a single blank line.

I hope that helps.