Root URL

Is there any way to make this plugin use root URL?

For example, right now the default to access this knowledge base is:
http://www.foo.com/knowledgebase

I want to make my main site to knowledge base. So that when opening http://www.foo.com will take me to the knowledge base instead of my main wordpress site.

Anyone can share some ideas?

Thanks!

https://wordpress.org/plugins/wp-knowledgebase/