How to finalize multiplayer game in UE4?

Hey guys, I have a game made that’s ready to go and I want to integrate a multiplayer feature. Multiplayer is handled just fine inside the editor, I’m able to have 2+ players run around and be in the same instance, however I am not sure on how to do it outside the editor. I packaged my game into *.exe form and I don’t know how to make a handler that runs a server/client relationship like I can in the editor. Can anyone help? Thanks.