How to simply connect two PC in a multiplayer game with connect the same wifi?

Hello Guys,I have been developing a project in almost one year.
And now the project will be done in a short time.
So at the last,I want to improve our project’s convenience to the players.
At this time,Our method to connect two PC in our game is to use the LAN.
But the players needed to connect with a VPN first to make sure they are in the same NET.
Now I want to ask is anyone know a simple method that can make two players connected with just connecting the same WIFI and don’t need to do other things(like:connect VPN first)

Thanks a lot !