These are some of the instructions they sent me when they unlocked an area for me for 3 months.
“Go to the DJI GO/DJI GO 4 App>Camera>General Setting>Unlocking List, tap "synchronize unlock information" to obtain the unlocking license;(Note: Please make sure the aircraft is placed within the area you requested to unlock and has good GPS signal before you tap and upload the license under the unlocking switch)
6、Enable the unlocking by sliding the corresponding switch, a green zone will appear on the map of DJI Go/ DJI Go 4 App, that’s the area you can fly your aircraft within;
7、After enabling the unlocking, you will only be able to fly in the unlocked area. You can disable the unlocking by sliding the switch;”