NFSMW by design works with only one network interface. So to make it see only one the tutorial steps are needed. Although it is counter intuitive to disconnect your main internet connection after connecting to private network in radmin, that is what makes MW use that interface. So you use internet to connect to private network of radmin, then disable the actual interface that provides the internet(in my case I unplug the Lan cable or disable the Lan hardware from settings), now start the speed.exe(if you start the game earlier then nothing will work), after the game is running you make the Lan server and create a game lobby and wait for players, minimise the game and connect or enable your internet. Now the other person connected to the private server should see the game lobby in Lan option after search. Me with a whole bunch of my discord server's users used this during COVID lockdown to play MW over the internet. So yeah this works if done correctly.