For openSUSE Tumbleweed run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:rhabacker:branches:windows:mingw:win64:Qt66:native/openSUSE_Tumbleweed/home:rhabacker:branches:windows:mingw:win64:Qt66:native.repo
zypper refresh
zypper install qt6-tools
For 15.6 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:rhabacker:branches:windows:mingw:win64:Qt66:native/15.6/home:rhabacker:branches:windows:mingw:win64:Qt66:native.repo
zypper refresh
zypper install qt6-tools
For 15.5 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:rhabacker:branches:windows:mingw:win64:Qt66:native/15.5/home:rhabacker:branches:windows:mingw:win64:Qt66:native.repo
zypper refresh
zypper install qt6-tools