This container can be pulled via:
  docker pull registry.opensuse.org/home/illuusio/images/images_15.6/nextcloud:15.6
  docker pull registry.opensuse.org/home/illuusio/images/images_15.6/nextcloud:30.0.4
  docker pull registry.opensuse.org/home/illuusio/images/images_15.6/nextcloud:30.0.4-5.27

Set DOCKER_CONTENT_TRUST=1 to enable image tag verification.