To enable two-step authentication with a mobile app, such as Google Authenticator, scan the QR code on the screen and confirm the code, then write down and store the provided backup code in a safe place.
If your authenticator app doesn't support syncing or exporting, then when switching to a new phone, you must use the "update" option on the authenticator app option and scan a new QR code on the new phone. This will invalidate the codes on the old phone.
To set up two-step authentication using a mobile app:
Make sure you have an authenticator app installed. Some examples are:
Google Authenticator (available for iOS and Android);
Click Add authentication method under the Two-step authentication section.
Select Use an authenticator app. You will be asked to scan the barcode on your screen with your mobile device’s camera.
Confirm the code that is shown on your device to finish the setup.
Write down the backup code shown and store it in a safe place.
The setup process is then complete. Going forward, Stripe will request a code when you sign in.
Additional Information
Unless you are using an authenticator app that syncs the secret key into the cloud or supports exporting the secret key, the generated codes are specific to the device and can't be transferred. Under such circumstances, if you are going to switch to a new phone or wipe your phone, you should use the update option to generate a new QR code to scan:
Note that this will invalidate the codes generated by previous device.