KAYA PRO subscriptions are managed by your app store.
By navigating to the "subscriptions" section of your app store, you can see when your free trial will expire and when you will get charged for a year-long subscription to KAYA PRO.
Keep in mind, KAYA cannot offer refunds once a subscription payment has been made, so if you do decide to cancel, make sure and cancel before your free trial expires! Click here for instructions for how to cancel your subscription.