There is no means to recover a recovery key.
However, a new recovery key - which supersedes all previous keys - can be easily generated from any of your trusted devices by following these instructions.
Set up a recovery key for your Apple ID - Apple Support
Note that use of a Recovery Key is entirely optional.
It’s NOT for everybody. (Especially IMO users with only a single trusted device)
… if you lose your recovery key and can’t access one of your trusted devices, you'll be locked out of your account permanently …
Establishing a recovery contact is a much more appropriate option for most users.