Wiki Login Page / Implementing Restrictions

Good Afternoon

I wish to lock down my wiki page so that it only shows a login screen for anyone trying to access it

I am running server.app and everytime I load up the wiki from inside and outside my office, it shows all the blog posts, documents etc

What do I change so that users require to login first before seeing anything?

Any help would be much appreciated.

Sam

Mac Mini 1TB 16GBram 2.6 GHz Intel Core i5

El Capitan 10.11.1 (15B42)