Link in billing email expired
Applies to G Suite, Google Drive Enterprise, and other paid subscriptions in your Google Admin console.
Some billing-related emails (to verify an email address or opt-out of receiving notifications, for example) contain links that have an expiration date. This helps prevent invitations from becoming outdated and accounts from being misused.
If you've received an expired link and need a new one, try a link from a more recent email or have an account administrator resend one to you.