For openSUSE Leap 15.4 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:xanders:branches:X11:RemoteDesktop/openSUSE_Leap_15.4/home:xanders:branches:X11:RemoteDesktop.repo
zypper refresh
zypper install xrdp
For openSUSE Leap 15.3 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:xanders:branches:X11:RemoteDesktop/openSUSE_Leap_15.3/home:xanders:branches:X11:RemoteDesktop.repo
zypper refresh
zypper install xrdp
For SLE 15 SP3 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:xanders:branches:X11:RemoteDesktop/SLE_15_SP3/home:xanders:branches:X11:RemoteDesktop.repo
zypper refresh
zypper install xrdp
For SLE 15 SP2 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:xanders:branches:X11:RemoteDesktop/SLE_15_SP2/home:xanders:branches:X11:RemoteDesktop.repo
zypper refresh
zypper install xrdp