The app doesn’t just magically know your router. It needs your phone to be connected to your Orbi WiFi. Then it talks to the router using the Orbi router login credentials. That’s the admin username and password, not your WiFi password. Lot of people mix that up. Default is usually admin and password. https://orbiloginet.com/why-cant-i-log-in-to-my-router-using-the-orbi-app/