How to show the same pop up in all my global network

Hi,
i would like to understand how to show the same pop up in all my 50 websites of my network.
Do i have to go in each website and create the same popup or this plugin can give me the faculty to create one popup and show it globally in all the websites? I ask you this because when i activate it i don't see any "popup plugin menu" showed in the network administration area.