SSH to the router and use

opkg update
opkg install luci 

But I don’t this will solve the port forward problem. In the default UI, you can port forward (both tcp and udp) 44158 from vpn zone to your Helium without problem.

The problem is that, does Torgaurd really give you an IP address that you can use port 44158?

What I heard is that you can never do this with commercial VPN providers. A dedicated IP does not mean you own that IP address and you can use all the ports.