For openSUSE Tumbleweed run the following as root:
zypper addrepo https://download.opensuse.org/repositories/Linux-PAM/openSUSE_Tumbleweed/Linux-PAM.repo
zypper refresh
zypper install passwdqc
For 15.6 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/Linux-PAM/15.6/Linux-PAM.repo
zypper refresh
zypper install passwdqc
For 15.5 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/Linux-PAM/15.5/Linux-PAM.repo
zypper refresh
zypper install passwdqc