Two-factor codes used for login can either be delivered via normal SMS or via the App.
Here is a description of how to quickly set up the App.
Download and install
In the app store on your phone search for SMS Passcode Mobile.
iPhone:
Android:
Register mobile number in the App
The first time, it is necessary to register which mobile number is associated with the App.
Enter mobile number after which you will be sent a two-factor code to enter.
Subsequently, you will now have two-factor delivered in the App.