This is another solution:
This is the way to format a card as recommended by Parrot Helpline,
1. Insert the ORIGINAL SD card that came with the Anafi drone.
2. turn on the drone and connect the controller to the phone with the free-flight 6 application
3. go to the gallery
4. select SD card
5. after select "format" the app show a new window with two option...now don't touch the smarthpone!
6. power off the drone.
7. take off the original SD card and insert the new SD in the drone.
8. Power on the drone again
9. format now the new card
10. Restart the drone.