When the trial is over, the App Store will automatically charge your Apple ID’s default payment method.
When you go forward, the subscription will auto-renew based on the app’s subscription model. For example, Panna offers monthly and annual subscriptions, whereas 1Password offers a yearly subscription.
When you try an app, and later you decide that you do not want to pay for it anymore, you can cancel the free trial at any time.
The process amounts to opening the Settings app then choosing your Name then iTunes & App Store > Apple ID > View Apple ID and then Subscriptions.
Next, to start following the prompts, go to the app you want to follow the prompts of, and select to cancel the subscription.
The good part is that your free trial doesn’t end the second you cancel it.
If you change your mind and decision, sign back for the paid subscription, and you can still have access to keep using the trial until your renewal date ends.
Apple says that, if you possibly change your mind and want to cancel a free or discounted subscription then it is better to do it within 24 hours, before your renewal date. Otherwise, you may still have to pay an amount for it.
Source URL: https://www.printer-customer-support.com/blog/apple-releasing-free-trials-for-ios-app-store/