Для openSUSE Tumbleweed запустите от имени root:
zypper addrepo https://download.opensuse.org/repositories/devel:languages:perl:CPAN-N/openSUSE_Tumbleweed/devel:languages:perl:CPAN-N.repo
zypper refresh
zypper install perl-Net-IDN-Encode
Для 15.5 запустите от имени root:
zypper addrepo https://download.opensuse.org/repositories/devel:languages:perl:CPAN-N/15.5/devel:languages:perl:CPAN-N.repo
zypper refresh
zypper install perl-Net-IDN-Encode
Для 15.4 запустите от имени root:
zypper addrepo https://download.opensuse.org/repositories/devel:languages:perl:CPAN-N/15.4/devel:languages:perl:CPAN-N.repo
zypper refresh
zypper install perl-Net-IDN-Encode