For openSUSE Tumbleweed run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:ecsos:fritzbox:RogerRouter/openSUSE_Tumbleweed/home:ecsos:fritzbox:RogerRouter.repo
zypper refresh
zypper install librm
For 15.6 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:ecsos:fritzbox:RogerRouter/15.6/home:ecsos:fritzbox:RogerRouter.repo
zypper refresh
zypper install librm
For 15.5 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:ecsos:fritzbox:RogerRouter/15.5/home:ecsos:fritzbox:RogerRouter.repo
zypper refresh
zypper install librm