Для openSUSE Tumbleweed запустите от имени root:
zypper addrepo https://download.opensuse.org/repositories/home:weberho:branches:server:php:applications/openSUSE_Tumbleweed/home:weberho:branches:server:php:applications.repo
zypper refresh
zypper install processwire3
Для 15.6 запустите от имени root:
zypper addrepo https://download.opensuse.org/repositories/home:weberho:branches:server:php:applications/15.6/home:weberho:branches:server:php:applications.repo
zypper refresh
zypper install processwire3
Для 15.5 запустите от имени root:
zypper addrepo https://download.opensuse.org/repositories/home:weberho:branches:server:php:applications/15.5/home:weberho:branches:server:php:applications.repo
zypper refresh
zypper install processwire3