Two-Factor Authentication enrolled now in auto Unlock Mac running on macOS sierra using Apple watch (watchOS3). And that’s also very useful for the security reason for the business or professional person. For the case your Apple ID login password cheats or leaked/ known by someone, still they need to pass one more security barrier that’s not passing out without your iPhone or iPad. When you login your Apple ID from any platform web browser or Devices, You will receive six digit Apple ID verification code after Setup two-Factor Authentication on Apple ID.
For the information: Please keep mind, Two step authentication (Get Six digit code on screen from apple) and Two step verification (Q&A for verify) both are different types for security features for login your Account.
All the time you will get verification code on trusted device only, So pick right device at first from you have (That may be your iPhone/ iPad/ iPod Touch or Mac running on iOS 9 or EI Capitan).
Trusted Phone number, Submit your personal primary contact number. In that number you will also get text message.
Every time you will get verification code on trusted device and Trusted number, when you sign in on new device or Browser.
Setup two-Factor Authentication on Apple ID from iOS device or Mac
Keep trusted Device as iPhone/ iPad/ iPod Touch
Step 1: Go to the Settings on iPhone
Step 2: Next, Tap on iCloud > Apple ID
Step 3: Then, Enter Apple ID password > Password & Security.
Step 4: Scroll Down and Tap on Two-Factor Authentication. (There you can add/ Update trusted Phone number for Apple ID)
Keep trusted Device as Mac, Follow the Steps on
Step 1: Go to the Apple Menu > System Preference.
Step 2: Then iCloud > Account Details > Security Section.
Step 3: Click on Two-Factor Authentication.
That’s it. More help and suggestion about Setup two-Factor Authentication on Apple ID. That’s disappointing you and still in your mind, Share with us on comment. We will appreciate your feedback always.