You’re welcome. Podman should be easy to learn for you as you already used Docker.
The advantage of podman over docker is to be able to run containers as user instead of root which provides better security.
The instance environments are user environments.
Either enter the container and use vi that’s available any container…
runagent -m nextcloud1 podman exec -ti nextcloud-app vi config/config.php
…or use following command to use the local nano editor instead of vi in the container:
Some more information about podman and use with NS8:
Podman docs: What is Podman? — Podman documentation