Troubleshooting & messages · Licence, trial and sign-in messages
What does "That code was issued for a different Mac" mean?
Short answer: Each code belongs to the Mac that requested it, and this one was requested elsewhere. Request a new code from this Mac and use it.
Verification codes are tied to the Mac that asked for them. You're entering a code that was requested on a different Mac (or a different installation), so it can't be used here.
Request a new code from this Mac and use that one.