For openSUSE Tumbleweed run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:Simmphonie:kicad/openSUSE_Tumbleweed/home:Simmphonie:kicad.repo
zypper refresh
zypper install kicad
For 15.6 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:Simmphonie:kicad/15.6/home:Simmphonie:kicad.repo
zypper refresh
zypper install kicad
For 15.5 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:Simmphonie:kicad/15.5/home:Simmphonie:kicad.repo
zypper refresh
zypper install kicad