For openSUSE Leap 156 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:mlin7442:rebuild_fails_156:gnuhealth/openSUSE_Leap_156/home:mlin7442:rebuild_fails_156:gnuhealth.repo
zypper refresh
zypper install mygnuhealth
For openSUSE Backports SLE-15-SP6 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:mlin7442:rebuild_fails_156:gnuhealth/openSUSE_Backports_SLE-15-SP6/home:mlin7442:rebuild_fails_156:gnuhealth.repo
zypper refresh
zypper install mygnuhealth