First, log in to your Stripe account using your username and password. Once you've logged in, head over to "Customers" tab under the "General" menu on the left side of the page.
From the "Customers" tab, select the email address or name of the client who recently canceled their individual training plan.
Then, in the client info page, scroll down to the bottom and locate the red "Delete Customer" button.
Click "Delete Customer" and, in the pop-up window, confirm the delete by clicking "Close account."