How do I unblock unknown numbers on my iPhone 14?

Are you referring to numbers you've blocked on your iPhone to prevent a call from such a number from ringing on your phone? If that's what you mean, see:

Block phone numbers, contacts, and emails on your iPhone or iPad - Apple Support

Once you are viewing the blocked contacts you can then remove any you wish.

If that's not what you're referring to, please explain further.

Regards.

Settings > Scan down to the bottom and tap Apps > Look for Phone > Turn off Silence Unknown Callers