For openSUSE Tumbleweed run the following as root:
zypper addrepo https://download.opensuse.org/repositories/isv:OpenCloud/openSUSE_Tumbleweed/isv:OpenCloud.repo
zypper refresh
zypper install opencloud-dolphin
For openSUSE Slowroll run the following as root:
zypper addrepo https://download.opensuse.org/repositories/isv:OpenCloud/openSUSE_Slowroll/isv:OpenCloud.repo
zypper refresh
zypper install opencloud-dolphin
For 15.6 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/isv:OpenCloud/15.6/isv:OpenCloud.repo
zypper refresh
zypper install opencloud-dolphin