If you can not receive the SMS authentication code, it is recommended that you change the security item according to Security Settings Change Guidelines to ensure your normal use.
iOS users can log into App Store and search “Authenticator” to download.
Android users can log into Google Play or search “Google Authenticator” in your mobile browser to download.
Open GA and scan the QR code below or enter the key to add a token.
This key is used to retrieve your GA when you change or lose your phone. Please save and back up the key before binding GA.