For openSUSE Leap 15.3 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:yfjiang:home:yfjiang:gnome:stable41:infra/openSUSE_Leap_15.3/home:yfjiang:home:yfjiang:gnome:stable41:infra.repo
zypper refresh
zypper install rpm
For SLE 15 SP4 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:yfjiang:home:yfjiang:gnome:stable41:infra/SLE_15_SP4/home:yfjiang:home:yfjiang:gnome:stable41:infra.repo
zypper refresh
zypper install rpm