Port Forwarding with two routers

[mikebali]

Hello guys, I was wondering if anyone would be able to assist with setting up Port Forwarding on my Sky router.

I have a second router connected (via ethernet) to Sky and the internet is working fine. 

Next, I need to setup Port Forwarding on the Sky Router to allow Router 2  to connect to this router via a VPN server when I'm outside the home network. 

I've searched the internet and found articles on setting up Port Forwarding with Sky routers but I was running into trouble setting it up and this article is from 2017 so some of the steps seem different when I log into my Sky hub. 

Any help setting this up (from the Sky router) would be much appreciated. 

[GD1]

@mikebali  Why are you using 2 routers?  You're asking for complications doing this, just use one router and then access points or network switches to expand your network.

[mikebali]

Thanks for the reply. This is the way I need it setup. 
Would you know how to setup this port forwarding? 

[mikebali]

I've opened a port of Sky and added the firewall rule but when I test to see if the port is open it says it's closed. Any idea why this might happen?