Support
Email support@ringside.help and a person answers. Include what you were doing and roughly when, and if it's about one meeting, its title and date.
Delete your account and everything in it: email the same address from the address you signed in with, and say so. Everything is deleted within 30 days and we confirm when it's done.
Revoke Ringside's access to your Google account at any time from your Google permissions page, or by signing out inside the extension. Either one destroys the stored token.