Firstly, we need to place an order, to check the functionality of the extension we would select the payment method set at the backend to cancel the order.
Suppose the settings made at the backend is as shown in the image below.

Place the Order
Let us create three orders having different payment methods, as mentioned in the general settings of the extension.

All three orders created are in pending status, Now as in backend within 2 min all these orders will get cancelled automatically and an email will be sent to the customer informing that the order has been canceled.