I have to echo what others have said, and tell you exposing your router’s login to the public internet is very risky (if you’re referring to the WiFi router in your home). I would strongly recommend some other solution to whatever broader problem you’re trying to solve with this—why do you need to access your router login from outside your home? Can the logging in (and presumably tinkering) be done at home? Definitely things to think through before proceeding.