For SLE 15 SP5 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:waldt:branches:network:ha-clustering:sap-deployments:devel/SLE_15_SP5/home:waldt:branches:network:ha-clustering:sap-deployments:devel.repo
zypper refresh
zypper install loki
For SLE 15 SP4 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:waldt:branches:network:ha-clustering:sap-deployments:devel/SLE_15_SP4/home:waldt:branches:network:ha-clustering:sap-deployments:devel.repo
zypper refresh
zypper install loki