For openSUSE Tumbleweed run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:DocB:Orthanc/openSUSE_Tumbleweed/home:DocB:Orthanc.repo
zypper refresh
zypper install orthanc-mysql
For 15.6 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:DocB:Orthanc/15.6/home:DocB:Orthanc.repo
zypper refresh
zypper install orthanc-mysql
For 15.5 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:DocB:Orthanc/15.5/home:DocB:Orthanc.repo
zypper refresh
zypper install orthanc-mysql
For 15.4 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:DocB:Orthanc/15.4/home:DocB:Orthanc.repo
zypper refresh
zypper install orthanc-mysql