For openSUSE Tumbleweed run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:tinita:perlmodules/openSUSE_Tumbleweed/home:tinita:perlmodules.repo
zypper refresh
zypper install perl-YAML-PP
For 15.6 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:tinita:perlmodules/15.6/home:tinita:perlmodules.repo
zypper refresh
zypper install perl-YAML-PP
For 15.5 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:tinita:perlmodules/15.5/home:tinita:perlmodules.repo
zypper refresh
zypper install perl-YAML-PP