For openSUSE Tumbleweed run the following as root:
zypper addrepo https://download.opensuse.org/repositories/Documentation:Tools/openSUSE_Tumbleweed/Documentation:Tools.repo
zypper refresh
zypper install lector
For 16.0 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/Documentation:Tools/16.0/Documentation:Tools.repo
zypper refresh
zypper install lector
For 15.7 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/Documentation:Tools/15.7/Documentation:Tools.repo
zypper refresh
zypper install lector
For 15.6 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/Documentation:Tools/15.6/Documentation:Tools.repo
zypper refresh
zypper install lector