You can do that through editor, make 2 shortcuts of unreal editor .exe, in the Properties->Target add this after shortcut directory.
- For listen server: [your directory of .uproject] [Map name]?listen -game. Ex: C:\ShooterGame\ShooterGame.uproject Test?listen -game
- For client: [your directory of .uproject] [Map name] [server ip] -game. Ex: C:\ShooterGame\ShooterGame.uproject 127.0.0.1 -game