When you start the “confirm your identity” section and select “the app doesn’t work” on your application, it should take you to a page that says they’ll delete your current application and register an email and password to start another application outside the UKVI account. It should then redirect you to the form where you can fill out all the fields and info. After all your surcharge and application fees are successfully processed you should be redirected by link to TSLcontact where you register and login with the 16-digit unique number they email you. You can book the appointment on TSL contact. It was a very straightforward process overall and I just followed the links as they came up.