How do a request a new recovery key

using Yosemite or later?

You may be able to attempt to login three times in a row, and then be offered use of your iCloud account and password to log in.

Use FileVault to encrypt the startup disk on your Mac - Apple Support

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If you lost your Recovery Key

As long as you remember your Apple ID password and still have access to one of your trusted devices, you can sign in and create a new Recovery Key.

1. Go to your Apple ID account page.
2. Sign in with your password and trusted device.
3. In the Security section, click Edit > Replace Lost Key.

Keep your new Recovery Key in a safe place. Your old Recovery Key won't work anymore and you can't use it to reset your password or access your account.

The above is from here...If you can't sign in with two-step verification using your Apple ID - Apple Support

More info you may need...Change or reset the password of a macOS user account - Apple Support

Also...https://support.apple.com/en-ca/guide/mac-help/mh35902/mac