Setting server password
To set server password go to My servers > Configure. You can see the current password by clicking show password:
To change the password, scroll down and find Server Password.
Once you type your new password, scroll down again and click .
Every player who wants to join the game, has to know the Server Password.
Using Allowed/Banned players
Go to My Servers > Configure > Players
You can easily allow or ban any player who has the Steam account. Additionally, you can sign an admin as well. All possible with just a Steam ID.
It is highly recommended to connect your Steam Account with Steam ID. With this easy step you will be able to upload your Friends list from Steam and add/ban when needed.
If there is nobody added to the allowed players section, everyone who has the server password is able to join the game. Once you add at least 1 allowed player, your server becomes private.
Then, only people from the Allowed players list can join the game.
If you prefer to keep players away, you can easily ban them:
Granting Admin privileges
You can add admin and grant extra privileges.