openSUSE Leap 15.4 (stable version):
sudo zypper ar -f https://download.opensuse.org/repositories/Application:/Astrophotography/15.4/ Astrophotography_Software
openSUSE Tumbleweed (rolling release):
sudo zypper ar -f https://download.opensuse.org/repositories/Application:/Astrophotography/openSUSE_Tumbleweed/ Astrophotography_Software