For openSUSE Leap 15.6 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/KDE:Extra/openSUSE_Leap_15.6/KDE:Extra.repo
zypper refresh
zypper install kcm_tablet
For openSUSE Leap 15.5 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/KDE:Extra/openSUSE_Leap_15.5/KDE:Extra.repo
zypper refresh
zypper install kcm_tablet
For KDE Applications openSUSE Leap 15.5 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/KDE:Extra/KDE_Applications_openSUSE_Leap_15.5/KDE:Extra.repo
zypper refresh
zypper install kcm_tablet