Two-factor authentication helps prevent others from accessing your > [your name] > Password & Security.
Tap Turn On Two-Factor Authentication, then tap Continue.
Enter a trusted phone number, a phone number where you want to receive verification codes for two-factor authentication.
You can choose to receive the codes by text message or automated phone call.
Tap Next.
Enter the verification code sent to your trusted phone number.
To send or resend a verification code, tap “Didn’t get a verification code?”
You won’t be asked for a verification code again on your iPod touch unless you sign out completely, erase your iPod touch, sign in to your signed in with your Apple ID.)
Obtain the verification at a trusted phone number: If a trusted device isn’t available, tap “Didn’t get a verification code?” then choose a phone number.
Obtain the verification code on a trusted device that’s offline: On a trusted iPhone, iPad, or iPod touch, go to Settings > [your name] > Password & Security, then tap Get Verification Code. On a trusted Mac with macOS 10.15 or later, choose Apple menu > [your name].
A list of the devices associated with your Apple ID appears near the bottom of the screen.
To see if a listed device is trusted, tap it, then look for “This device is trusted and can receive Apple ID verification codes.”
To remove a device, tap it, then tap Remove from Account.
Removing a trusted device ensures that it can no longer display verification codes and that access to iCloud (and other Apple services on the device) is blocked until you sign in again with two-factor authentication.
With two-factor authentication, you need an app-specific password to sign in to your Apple ID account from a third-party app or service—such as an email, contacts, or calendar app. After you generate the app-specific password, use it to sign in to your Apple ID account from the app and access the information you store in iCloud.
Sign in to your Using app-specific passwords.