This article with show you how you can add a password to your Don't Starve Together server.
On the "Game Settings" page of your control panel, add a password you'd like to use in the "Server Password" text box field.
Remember to Save your changes and Restart your server!
If you don't have access to our NodePanel, you'll need to add your password into the
cluster.ini file. This file is located in
[Network] header in this file, you'll add your password into the
Save your changes and give your server a good Restart and your server will be password protected!