If you only want one week of the Membership or wish to cancel or pause your Subscription, you can do so through the App Store. If you don't wish for it to be renewed, make sure to make changes at least 24 hours before your next billing period
 
After successfully canceling or pausing your Subscription, your benefits will continue through the week. If you only intend to get one week, we recommend unsubscribing immediately so you do not forget at the end of the week.
 
To cancel a Subscription, you need to go through your 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" or "Pause Payments"
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