For openSUSE Leap 15.3 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/devel:languages:perl/openSUSE_Leap_15.3/devel:languages:perl.repo
zypper refresh
zypper install perl-IP-Country
For SLE 15 SP4 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/devel:languages:perl/SLE_15_SP4/devel:languages:perl.repo
zypper refresh
zypper install perl-IP-Country
For SLE 15 SP3 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/devel:languages:perl/SLE_15_SP3/devel:languages:perl.repo
zypper refresh
zypper install perl-IP-Country