How to cancel your Google Workspace subscription

Step 1: Log in to Google Workspace Admin with your user credentials. Then Navigate to Billing and select Subscriptions.

Step 2: Select the relevant workspace subscription (if there is more than one) and go to More. Now click on Cancel subscriptions.
Select a reason for cancellation and confirm the selection with Next.

To proceed, confirm your selection with Cancel subscription and enter your Google address again. Then You should now
receive an automatic cancellation confirmation via email. The cancellation should be completed in 84 days at the latest.

Credit : https://www.ionos.com/digitalguide/e-mail/technical-matters/cancel-google-workspace/