You can cancel your subscription from your iPhone by following these steps
Open the Settings app.
Tap your name.
Tap Subscriptions.
Tap the subscription you want to cancel.
Tap Cancel Subscription. You might need to scroll down to find the Cancel Subscription button. If there is no Cancel button or you see an expiration message in red text, the subscription is already canceled.
With the Free Trial, you can try all the features and functionalities of this app free for the trial period. If you start the free trial and cancel your subscription at-least 24 hours prior to the end of the free trial period, you will not be charged.