I don’t remember my 28 recovery key code

See -> Two-step verification for Apple ID

Two-step verification for Apple ID

👉 scroll to & read -> What if I lose my Recovery Key?

You can sign in to your Apple ID account page and create a new Recovery Key using your Apple ID password and one of your trusted devices.

1. Go to appleid.apple.com/uk.
2. Sign in with your password and trusted device.
3. In the Sign-In and Security section, click Recovery Key > Change Recovery Key.

Keep your new Recovery Key in a safe place. Your old Recovery Key won't work any more and you can't use it to reset your password or access your account. If you can't see Recovery Key in the Sign-In and Security section, then you are not using two-step verification. 

👉 FYI: Write down your recovery key and keep it in a safe place.

See this link to generate a new recovery code

How to generate a recovery key - Apple Support