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