Welcome to this page. This article will teaches you how you can fight against criminals by muting them.
If you didn't set your moderation channels you should visit the following article:
Anyway, how you can define a role. Simply, by typing
y!config edit muteRole <rolename>
And this module will don't work without setting the moderation channel up. This only works if the moderation channel/muted role are setted up correctly.