Problem Installing Xprivacy: Where is the Install Button?

I'm trying to install Xprivacy, but I can not find the install button.
When I click on the app logo on my phone, the following screen appears.

If you click "root", the new message "Device is rooted" appears.
Although I'm pretty sure it is not.
Probably the missing check mark means that it is not rooted (a bit confusing).

I assume that I first have to root the phone

Right ?