To unlock the Dark Zone: Extraction achievement in The Division 2, you will need to extract loot from all three of the game's Dark Zones.
The Division 2 Dark Zones:
- DZ East
- DZ South
- DZ west
You unlock the ability to enter Dark Zones after you recruit Senait Ezera from the Theater district. Once she is recruited, return to the White House and talk to her. She will give you a tutorial mission for DZ East. Completing the tutorial will unlock another tutorial for DZ South. Completing that will unlock a final tutorial for DZ West.
Once you have completed the three Dark Zone tutorial missions, you will gain full access to each of them.
To unlock the achievement, you will simply need to visit each Dark Zone, find some loot, enter the extraction point highlighted on the map and fire a flare to call the extraction helicopter. Wait for the chopper to arrive and defend your position so that you nobody steals what you have, attach your loot to it and wait until the chopper leaves.
Once you have recovered at least one item from each of the three Dark Zones, the achievement will unlock.