For openSUSE Tumbleweed run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:wkazubski:drivers:v03/openSUSE_Tumbleweed/home:wkazubski:drivers:v03.repo
zypper refresh
zypper install xf86-input-synaptics
For 15.6 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:wkazubski:drivers:v03/15.6/home:wkazubski:drivers:v03.repo
zypper refresh
zypper install xf86-input-synaptics
For 15.5 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:wkazubski:drivers:v03/15.5/home:wkazubski:drivers:v03.repo
zypper refresh
zypper install xf86-input-synaptics