Alles anzeigenOMV has a wireguard plugin as a VPN if you prefer that, as speeds for wireguard are probably faster than tailscale.
As I said above, a VPN connects your remote device to your server, but you need to access local things based on their IP address.
Also as I said above, you need to port forward 80 and 443 to the NPM container and set up your services in NPM. Just having NPM running does nothing if you don't set up the services.
For example: If your OMV server is IP 192.168.0.200, and the NPM container is on port 80 and 443, you need to set OMV to use a different port, and your router needs to port forward 80 & 443 to 192.168.0.200.
If you are running Emby for example, it would default to port 8096, so then NPM needs to have an entry for emby.yourdomain.duckdns.org pointing to 192.168.0.200 on port 8096. or you can place all of your docker containers on a custom docker network and use the container name instead of 192.168.0.200 (container names do not work on the default docker network.
You should also enable ssl in NPM for the services so your traffic is not visible to someone that may intercept it.
It is no more complicated than that, just as I said above.
Ask me a question, please. For example, being my DuckDNS domain "teste123.duckdns.org", if I want to configure Emby on NPM, do I put teste123.duckdns.org with port 8096 on the NPM hosts or do I put emby.teste123.duckdns.org? Looking at some videos I was in doubt because the examples suggested that I would need to create a domain for each service on DuckDNS.