For openSUSE Tumbleweed run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:ph03nix/openSUSE_Tumbleweed/home:ph03nix.repo
zypper refresh
zypper install go-mod-upgrade
For 15.6 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:ph03nix/15.6/home:ph03nix.repo
zypper refresh
zypper install go-mod-upgrade
For 15.5 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:ph03nix/15.5/home:ph03nix.repo
zypper refresh
zypper install go-mod-upgrade