For openSUSE Tumbleweed run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:urbic:java/openSUSE_Tumbleweed/home:urbic:java.repo
zypper refresh
zypper install lept4j
For 15.6 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:urbic:java/15.6/home:urbic:java.repo
zypper refresh
zypper install lept4j
For 15.5 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:urbic:java/15.5/home:urbic:java.repo
zypper refresh
zypper install lept4j