For openSUSE Tumbleweed run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:markusd:samba-fresh-fs/openSUSE_Tumbleweed/home:markusd:samba-fresh-fs.repo
zypper refresh
zypper install samba-ad-dc
For 15.6 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:markusd:samba-fresh-fs/15.6/home:markusd:samba-fresh-fs.repo
zypper refresh
zypper install samba-ad-dc
For 15.5 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:markusd:samba-fresh-fs/15.5/home:markusd:samba-fresh-fs.repo
zypper refresh
zypper install samba-ad-dc