How do I add a local IP address to the list of trusted domains in Firebase?

Currently, localhost is on the list of trusted domains in Oauth settings in my Firebase app. However, I cannot add the local IP address of my machine to this list, it says something along the lines of "provide a real address". I need it so that I can test the app on a mobile phone, I can't just type "localhost:3000" in the address bar on the phone, it's only possible with "192.168.2.103:3000" which is, again, not on the list.