For openSUSE Tumbleweed standard run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:Sauerland:branches:home:Sauerland/openSUSE_Tumbleweed_standard/home:Sauerland:branches:home:Sauerland.repo
zypper refresh
zypper install hplip-hpijs
For openSUSE Leap 15.2 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:Sauerland:branches:home:Sauerland/openSUSE_Leap_15.2/home:Sauerland:branches:home:Sauerland.repo
zypper refresh
zypper install hplip-hpijs
For openSUSE Leap 15.1 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:Sauerland:branches:home:Sauerland/openSUSE_Leap_15.1/home:Sauerland:branches:home:Sauerland.repo
zypper refresh
zypper install hplip-hpijs