How do I set up an Apple Account login verification KEY or QR Code

You don’t.

Your AppleID is protected by Apple’s own cryptologically-based 2FA.

Those fields within “Passwords” are for other web sites that use Timed One Time Passwords (TOTP) as part of their authentication process.

i.e. It replaces the need for a separate Authenticator App on your device (e.g. Google Authenticator).

Learn how Apple’s 2FA works and how to configure it from here:

Two-factor authentication for Apple ID - Apple Support