For openSUSE Tumbleweed run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:mnhauke:monitoring/openSUSE_Tumbleweed/home:mnhauke:monitoring.repo
zypper refresh
zypper install monit
For 15.6 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:mnhauke:monitoring/15.6/home:mnhauke:monitoring.repo
zypper refresh
zypper install monit
For 15.5 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:mnhauke:monitoring/15.5/home:mnhauke:monitoring.repo
zypper refresh
zypper install monit
For 15.4 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:mnhauke:monitoring/15.4/home:mnhauke:monitoring.repo
zypper refresh
zypper install monit