For openSUSE Tumbleweed run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:raspher/openSUSE_Tumbleweed/home:raspher.repo
zypper refresh
zypper install gtk4-layer-shell
For openSUSE Slowroll run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:raspher/openSUSE_Slowroll/home:raspher.repo
zypper refresh
zypper install gtk4-layer-shell
For 16.0 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:raspher/16.0/home:raspher.repo
zypper refresh
zypper install gtk4-layer-shell
For 15.6 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:raspher/15.6/home:raspher.repo
zypper refresh
zypper install gtk4-layer-shell