Most likely just plain http, no s at the end. You would normally just put 192.168.1.254 into the address bar, assuming it's a hub, or what ever the LAN IP is for the router in use. EG: 192.168.0.1 for some others. It's on your LAN and can only be accessed from the LAN and so is already secure.
Another example, when I copy the visible url for the router in the address bar here it returns http://192.168.0.1/