The new token migration can be managed via the 'User profile' option on top of the page. If you need to generate a new QR code in case that you have changed your device you can process it here.
After entering your profile, there you will have an option to request a new QR code by clicking on the 'Generate New QR-code'.
The pop-up will inform you to finish the process, otherwise, your process will be incomplete and you will be able to log in only using a fallback phone number as a token.
Once you press on confirm, a new QR-code will appear, then with the help of an authenticator app, you will be able to read and confirm your mobile device.