Testing multiplayer with another IP

Hello everyone, I’d like to test multiplayer on my game with someone else on a different PC in a different location, but do not have any menus or settings configured for joining/leaving sessions. Is there any quick way to test multiplayer using just the command line? What is the quickest way for me to test this?

when i run multiplayer tests i bind a key to enter a console command : open

then on my machine i use the console command : open your_mapname_here?listen
this will allow them to connect to you just make sure you open port 7777

Would I open the port in my router settings?