The settings are defined in the config file on line 16.
<property name="ServerVisibility" value="2"/> <!-- Visibility of this server: 2 = public, 1 = only shown to friends, 0 = not listed. As you are never friend of a dedicated server setting this to "1" will only work when the first player connects manually by IP. -->
You will also need to have set the Region (line 11) and Language (line 12) options.