To use the Google Authenticator Sync feature, you will need to update the Google Authenticator app on all of your devices.
Once you have updated the app, you will be prompted to sign in to your Google Account. After you have signed in, you will be able to sync your 2FA codes.
Steps
Open the Google Authenticator app on one of your devices.
Tap the Menu button (three horizontal lines).
Tap Settings.
Tap Sync.
Follow the on-screen instructions.
Once you have completed these steps, your 2FA codes will be synced across all of your devices.
Update App on Android
Open the Google Play Store app.
Tap the Profile icon in the top right corner of the screen.
Tap Manage apps & devices.
Tap Manage under Updates available.
Tap Update next to the Google Authenticator app.
Update App on iPhone
Open the App Store app.
Tap the Profile icon in the top right corner of the screen.
Tap Updates.
Tap Update next to the Google Authenticator app.
