To cancel your subscription, click on your name in the top right-hand corner of your screen and then select "Profile" as shown in the image below.
Scroll down to the bottom of the page and click on the red "Delete Account" button as shown in the image below.
PLEASE NOTE: You will immediately lose access to Projection Genie and any projects you created will be permanently deleted. You will not be able to retrieve any of your deleted data if you later change your mind, so be 100% sure you want to cancel your subscription.