How to lock router

Hi, I want to connect MT300N in repeater mode to a network and run wireguard. It is a public network and therefore I don’t want anyone to know it is a router and sniff into router login page. Is there anyway I can lock router admin page so it fails to load once I do all settings? And is it possible to change router MAC address?

Public network won’t be able to access your router admin page, which is blocked by firewall by default.
You can use mac clone at web UI More Setings - Mac clone page.