According to some description, you define the area that you want to cover, and the program will display how many tiles you need, shape etc. I've checked the screenshots of the software and didn't see any form where you can enter the data to generate stats.
However, since the software does not appear to be available anymore, I recommend using the online version of the planner, offered by the developers: https://www.bradstone.com/garden-guides-advice/paving-planner/