When signing in with your username and password all Two-factor Authentication (2FA) settings will be enabled.
A sign in 2FA is required when signing in and Trading 2FA will be prompted when applicable. Trading 2FA is a separate 2FA method specifically for placing orders, so it is still possible to place a new order or modify an existing order via the app even though you have Trading 2FA enabled on your account.
2FA for API keys is not yet compatible with the app. If you have this set up on your API keys it will not be possible to access the app.