Remote Setup the Apps

My Router: Nighthawk RAX20 

I have setup a Netgear RAX20 in LA. I can setup the apps when I was in LA via local wifi connected. After I go to Hong Kong.I have to reset my phone in some reason. After I install the apps again.I cannot do the setup of the Nightawk apps. I cannot scan the QR code. I have click the Remote Managment by using port 8443. I can use remote intterface via Computer but i cannot use via apps on phone. I cannot type my WAN IP and my netgear DDNS on the apps.

Q1: I have been delete apps before I have to reset my phone. How can I setup the  Nighthawk RAX20  in Hong Kong without QR code and local wifi connecting?

Q2: Why there are no RAX20 select in model Bar in this page?

Sam 

Thank you

Mail: san64999418@gmail.com