Для 15.6 запустите от имени root:
zypper addrepo https://download.opensuse.org/repositories/home:tlusk:devtools/15.6/home:tlusk:devtools.repo
zypper refresh
zypper install procs
Для 15.5 запустите от имени root:
zypper addrepo https://download.opensuse.org/repositories/home:tlusk:devtools/15.5/home:tlusk:devtools.repo
zypper refresh
zypper install procs
Для 15.4 запустите от имени root:
zypper addrepo https://download.opensuse.org/repositories/home:tlusk:devtools/15.4/home:tlusk:devtools.repo
zypper refresh
zypper install procs