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. Click Cancel
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. Click Cancel
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