While most functions in our module do not depend on their IPN system, it is used for allowing them to notify our module when a client cancels a Billing Agreement directly from their PayPal account and disabling IPN will prevent that our module from receiving the notification and deleting the Pay Method from the client. Our module also checks for the Billing Agreement being cancelled while attempting to charge a payment via WHMCS and will delete the Pay Method from the client as well.
