You are only required to demonstrate you can fly in ATTI mode if your Drone can be flown in ATTI mode
If you have a drone that can be switched to ATTI mode (such as the DJI Phantom 4 and the DJI Inspire range) you will be required to demonstrate as part of your FLight Examination that you can fly safely in ATTI mode.
If your aircraft only has a GPS mode and can't be switched over to ATTI mode (unless it loses GPS signal) then you will only be tested as part of your flight examination in GPS mode. This applies to drones such as:
- DJI Mavic series
- DJI Spark
- Parrot ANAFI