To work, it requires some hardware, and an online account at app.jacktrip.org. You don't need to install any software on your computer- everything is controlled through the browser.
There are a few pieces of hardware each member of your group will need in order to connect online, including the JackTrip Bridge, which is the best way to connect to the Virtual Studio.
The JackTrip Analog Bridge has an audio interface in it, so you can just plug in your compatible microphone and headphones. The JackTrip Bridge is a tiny computer that runs the software necessary to connect the the Virtual Studio. It plugs into your router via an ethernet cable so that it can access the internet.