How do you configure the Unsubscribe option in Recruiting Cloud campaigns?

Summary:

Recruiting Cloud unsubscribe campaign feature doesn't seem to work.

Content (required):

When I add the unsubscribe element to the email template and send it to external community members, nothing is displayed that would give the recipient a way to unsubscribe. Is there documentation out there explaining how this is supposed to work? I'm sure I am jsut missing something, but I can't find any documented answers to this. Thanks!

Version (include the version you are using, if applicable):

21D

Code Snippet (add any code snippets that support your topic, if applicable):