When you tap “Connect to Infinite Flight” at the bottom of the screen, the app wil list the IP address of the device(s) running IF. When you select the right one, the app will connect to it.
“Enable Infinite Flight Connect” has to be checked in IF as well.
None of the apps will run on a Windows PC, but you can share the device’s screen with a PC.
LonelyScreen is one of the apps that you could use for iPhone/iPad screen sharing. For Android there are different tools.