For openSUSE Tumbleweed run the following as root:
zypper addrepo https://download.opensuse.org/repositories/science:unstable/openSUSE_Tumbleweed/science:unstable.repo
zypper refresh
zypper install ccx
For 15.6 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/science:unstable/15.6/science:unstable.repo
zypper refresh
zypper install ccx
For 15.5 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/science:unstable/15.5/science:unstable.repo
zypper refresh
zypper install ccx