A subscription bought in the Android app is managed by Google Play.
- Open the Google Play Store app and tap your profile picture.
- Tap Payments and subscriptions, then Subscriptions.
- Choose the app and tap Cancel subscription.
Make sure you are signed in to the same Google account you used to buy. Cancel before the next charge date. After cancelling, Premium stays active until the end of the paid period. See what happens after you cancel.
Menu names change between app and OS versions. Verify before publish against the current Apple and Google help pages.