Question regarding testing

What would be the best way to test a game with someone else? No matter how far along I am. As in, if I wanted to test networking with someone else or just assets with someone else.

Would a launcher do it? Or would I have to just repackage each build and send it to him?

I realize there is a built in multiplayer feature to test two clients with myself. That’s not what I’m asking. Any information would be appreciated.

I also just realized this is in the wrong section for this topic. I think I had thought of a different way to ask this before posting. I apologize.