1. On your new phone, install the Google Authenticator app.
  2. In the app, tap Get Started.
  3. At the bottom, tap Import existing accounts.
  4. On your old iPhone, create a QR code:
    1. In the Authenticator app, tap More and then Export accounts and then Continue.
    2. Select the accounts you want to transfer to your new phone, then tap Export.
    3. If you transfer multiple accounts, your old phone may create more than one QR code.
  5. On your new phone, tap Scan QR code.
  6. After you scan your QR codes, you get a confirmation that your Google Authenticator accounts transferred. You can remove your exported accounts from your old phone.


Original Article:

https://support.google.com/accounts/answer/1066447?hl=en&co=GENIE.Platform%3DiOS#zippy=%2Ctransfer-authenticator-codes-to-a-new-phone