For openSUSE Tumbleweed run the following as root:
zypper addrepo https://download.opensuse.org/repositories/systemsmanagement:cockpit/openSUSE_Tumbleweed/systemsmanagement:cockpit.repo
zypper refresh
zypper install local-npm-registry
For 15.5 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/systemsmanagement:cockpit/15.5/systemsmanagement:cockpit.repo
zypper refresh
zypper install local-npm-registry
For 15.4 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/systemsmanagement:cockpit/15.4/systemsmanagement:cockpit.repo
zypper refresh
zypper install local-npm-registry