How do I get affiliates entered into the Affiliates plugin?

I've installed the Affiliates plugin, and it's network activated. I see the Affiliates section in the admin section now, but I don't see any way to add affiliates to the system.

If I visit the "manage affiliates" section, there's a utility for sorting and organizing affiliates, but I don't see anywhere for an affiliate to sign up or for me to add them manually even.

I've visited the documentation for this plugin also, and I'm not seeing this addressed anywhere. Am I looking in the wrong place? All I see is a "set up instructions" page, but there's nothing there that addresses this either.

I feel like I must be missing something very basic. Any insight is much appreciated!