Exposing ports and making yunohost accessable outside network

I’m trying to set up yunohost, but I get stuck at this screen.

I’m running yunohost on virtualbox where it’s ipaddress is V. The ipaddress of this computer is C.

I have tried to port forward 20 and 443 to ipaddress V and apply the settings, but the diagnostics doesn’t change. Does the port forwarding has to go from the router to C to V maybe?

The service Nginx is running on yunohost.

I’m renting an apartment so if there’s a modem, then I don’t know about it.

Edit Added a picture in the replies about the router settings. (I’m sorry for bad format, just wasn’t allowed to add two images to original post).

I had some conversations with some other people who suggested I should install yunohost as the main OS instead. So I did that. But the diagnosis is still the same though.

First you’ll have to follow this tutorial :
The network adapter in the virtualbox should be bridged adapter.
To open ports, you’ll have to access the router interface, depending on the model.
Using a vpn may help you bypass the port forwarding on the router (I may be wrong, I did not test this solution)

I used the tutorial to get where I am right now. I have been using bridged adapter.

By the way, this is how the router settings looks like right now. Notably port forwarding is only under the NAT settings.

The private IP shouldn’t be the IP of the physical machine?

I don’t understand. I have used the ip address 192.168.x.y in the forwarding.