Once you install the plug-in, open Outlook and select Appointment from the new Appointment tab:

After that, type a name, a location and enter a starting and ending time. Next, click Room Booking to perform a search for an available room and press Find. Once Codeco finds all available rooms, click Book Now button:

For further information, I suggest you open the first link from Google search engine. Alternatively, use the Contact Us page to get in touch with the support team.