if you can follow these instructions, NS8-Generic Containers-: Install Uptime-kuma - Howto - NethServer Community
and modify them using the below command
using this command
docker run -d --name savapage -v /var/run/dbus:/var/run/dbus --privileged -v /sys/fs/cgroup:/sys/fs/cgroup:ro --net=host -p 8631:8631 -p 8632:8632 -p 9100:9100 -p 631:631 savapage amrhegazy/savapage
from here: amrhegazy/savapage - Docker Image | Docker Hub
i guess you should be able to install it on your server. the image is old, but so is the official repo
SavaPage / savapage-server · GitLab
A more complex angle would be to use this implementation by @mrmarkuz to implement an NS8 module
nethserver-savapage/nethserver-savapage.spec at master · mrmarkuz/nethserver-savapage (github.com)