Please tap "Premium" from the app's settings screen.
Premium is a subscription service available as a monthly or yearly plan. Once subscribed, ads will no longer be displayed during your subscription period.
While subscribed, other devices signed in with the same Apple ID can also be used ad-free by tapping the "Restore Premium Service" button ― no additional payment is required.
You can cancel your subscription at any time from the Subscriptions section in your device's Settings app.
In addition, if you previously purchased Premium as a one-time (lifetime) purchase, you may continue to use it free of charge forever. Even after switching to a new device or reinstalling the app, simply tap the "Restore Premium Service" button to resume use at no additional cost.