For openSUSE Tumbleweed run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:mike-fabian/openSUSE_Tumbleweed/home:mike-fabian.repo
zypper refresh
zypper install libm17n0
For 15.5 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:mike-fabian/15.5/home:mike-fabian.repo
zypper refresh
zypper install libm17n0
For 15.4 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:mike-fabian/15.4/home:mike-fabian.repo
zypper refresh
zypper install libm17n0