You may cancel your subscription by following the steps below.
Note: The subscription will auto renew annually or monthly depending on the option you purchased

iOS devices:
  1. Go to MORE tab
  2. Go to Manage Your Subscription
  3. Select Open for the pop up question(Open in "iTunes Store"?)
  4. Fill subscriber Apple ID and Password
  5. Click Track Meet Mobile/Meet Mobile Subscription
  6. Click Cancel Subscription
Or please refer to the link below to manage your account:
https://support.apple.com/en-us/HT202039

Android devices:
  1. Go to Meet icon
User-added image
  1. Go to Manage your subscription
  2. Fill subscriber Google play ID and Password
  3. Click Track Meet Mobile/Meet Mobile Subscription
  4. Click Cancel Subscription
Or please refer to the link below to manage your account: 
https://support.google.com/googleplay/answer/7018481?hl=en&ref_topic=1689236&co=GENIE.Platform%3DDesktop&oco=1
Note: If there is no Cancel Subscription button showing out after following the steps above, it means the subscription auto-renewal has already been turned off.