An unlock code for what? My Mavic Pro flies as well now as it did after the last firmware upgrade I allowed it to download load, maybe better as Superpatcher has been applied.
Yes, after more than 35 years experience with computers I understand the difference between ‘firmware’ for the drone and data updates for the fly safe database, though I hesitate to call an update to the drone operating system ‘firmware’, but...
Especially since the OP is coming from an iPhone as a video display.
No change at all in the operating system and app when switching to an iPad instead.