Flashpoints are a weekly occurrence in Destiny 2 and can take place on any planet/moon. They are acquired as milestones from Cayde-6 upon his return to the farm. The milestone goes as follows:
- Speak to Cayde-6 at the social space to start the Flashpoint Milestone
- Complete the Mission "Patrol" (The Importance of Networking) at EDZ to unlock Patrol Missions on every planet
- Complete 3 Patrol Missions at EDZ
- Travel back to the social space and speak to Cayde-6 again to receive a Legendary Engram and continue the milestone
- Go back to the EDZ and complete 6 public events (normal or heroic)
- Travel back to The Farm and speak to Cayde-6 yet again to receive another Legendary Engram, completing the milestone and unlocking the achievement
These steps will be more or less the same but on different planets during different weeks.