Two-step verification of your Apple ID is an added security feature to further secure your account. You need to verify your identity using an Apple device before you can manage your account. You'll also need to verify before you can purchase content from the App Store or iTunes.
Step
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Step 1. Visit the Apple ID website
Open a browser and type https://appleid.apple.com/. Press the “Enter” key on the keyboard to access the page.
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Step 2. Sign in to your Apple account
Type your Apple ID and password into the fields provided, then press the “Enter” key to sign in.
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Step 3. Access the “Password and Security” setting menu
Select the “Password and Security” option on the left side of the screen.
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Step 4. Answer the account security question
Just answer the question in the column provided on the right side of the screen. Click “Continue” when finished. After that, you will be taken to the verification page.
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Step 5. Verify the account
Click “Get Started” on the “Verification” page, then click “Continue” on the next “Verification” page.
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Step 6. Get the 4 digit code
This code will be sent to the iOS device used. Write down or remember the code.
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Step 7. Enter the 4 digit code
When you later log in to your account, just type in the 4-digit code sent to your iOS device. Perform this step to complete the verification process.