1. Go to Steam library > Right click on "The Long drive" > Properties > Betas > choose "Multiplayer_test - Multiplayer_test"

1. Start game.
   
2. Press "START".
   
3. When you in game press "T" key (Multiplayer menu).
   
4. Click "lobby"

Left side of menu is your lobby,right side is lobbys of others.

Left side:
There 3 strings to edit [Server name,Max player,Password] and 3 buttons to press [Server mode,Player spawn,Create].
When you editing strings ALWAYS press ENTER key after editing.
When you set setting press "Create".

Now your server exist, but there might be a small problem - your friend\you cant find server in list or connect through Steam. GO TO issues Section!

Well its simple you are on diffrent Steam downloading regions.

1. Goto Steam settings.
   
2. Click "Downloads".
   
3. Change "Download region" on SAME with your friend. it can be any.

Why is working like that? idk.