To cancel a Subscription, you need to go through your device's App Store.

On Android:
  1. Open the Play Store app, and confirm that you're signed into the correct Google account
  2. Open the menu on the top right and select "Payments & subscriptions"
  3. Select the Subscription you want to change
  4. Select "Manage"
  5. Select "Cancel Subscription"
More information can be found here: https://support.google.com/googleplay/answer/7018481

On iOS:
  1. Open the "Settings" app.
  2. Tap your name.
  3. Tap "Subscriptions" (If you don't see "Subscriptions," tap "iTunes & App Store" instead. Then tap your Apple ID, tap View Apple ID, sign in, scroll down to Subscriptions, and tap Subscriptions.)
  4. Tap the Subscription that you want to manage.
  5. Tap "Cancel Subscription." If you don’t see Cancel Subscription, the Subscription is already canceled and won't renew.
More information can be found here: https://support.apple.com/en-us/HT202039

After successfully canceling your Subscription, your benefits will continue through the week or month depending on the type of Subscription purchased.

If you don't wish for your Subscription to be renewed, make sure to make changes at least 24 hours before your next billing period to avoid being charged.