For openSUSE Tumbleweed run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:frispete:test/openSUSE_Tumbleweed/home:frispete:test.repo
zypper refresh
zypper install freerdp
For 15.5 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:frispete:test/15.5/home:frispete:test.repo
zypper refresh
zypper install freerdp
For 15.4 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:frispete:test/15.4/home:frispete:test.repo
zypper refresh
zypper install freerdp