On your other device, sign in to the area of the website or app where you manage your account, then select options to enable two-factor authentication and an authenticator app. A QR code appears to help you set up an authenticator app. On iPhone, use the camera to scan the QR code.

If you have a new phone, open the Google Authenticator app, tap +, and then Scan a QR code. Hold your new phone up to scan the QR code on your old phone's screen. If you don't have the new phone yet or want to save the code for later, you can take a screenshot and print it.