I tried step 5.1 and the following pull request fails:
[linux1@manrique ~]$ docker pull registry.linuxone.cloud.marist.edu/l1cc/jupyterlab-image-s390x:latest
permission denied while trying to connect to the Docker daemon socket at unix:///var/run/docker.sock: Post "http://%2Fvar%2Frun%2Fdocker.sock/v1.47/images/create?fromImage=registry.linuxone.cloud.marist.edu%2Fl1cc%2Fjupyterlab-image-s390x&tag=latest": dial unix /var/run/docker.sock: connect: permission denied
[linux1@manrique ~]$