Recovery key

If you generated a recovery key then it was up to you to keep that key and save it somewhere you could retrieve it if needed. It is not recoverable anywhere unless you saved it somewhere. And without it, you won’t be able to recover your AppleID. Apple support won’t be able to help as enabling a recovery key disables Apple support account recovery.

See -> How to generate a recovery key - Apple Support

”Using a recovery key is more secure, but it means that you’re responsible for maintaining access to your trusted devices and your recovery key. If you lose both of these items, you could be locked out of your account permanently. With that in mind, it's important to keep your recovery key in a safe place. You might want to give a copy of your recovery key to a family member, or keep copies in more than one place. That way you always have your recovery key when you need it.“

When you choose to enable an account recovery key, it is imperative that you record that key and save it somewhere safe so you can retrieve it if needed.