Xfinity mobile app doesn't show installed equipment

I want to use port forwarding on my xFi router. I can log into it on the Web, but this is not one of the options offered there, and you're supposed to use the mobile app. But when I logged into the mobile app it didn't list any equipment and prompted me to activate the modem (but it's already working). I'm afraid to attempt to activate it with the mobile app, wondering if that would disrupt my service. But I'd like to use that app for port forwarding once the xFi appears there. What should I do?