https://www.gamespot.com/articles/destiny-2-servers-down-for-maintenance-update-new-/1100-6454589/

If you're trying to play Destiny 2 right now, you should make new plans. Bungie has taken the game's servers offline for maintenance and will release a new update, version 1.0.6, later today. In the meantime, you'll be unable to log in, effectively rendering the game unplayable. [Update: Maintenance has concluded, and the new Destiny 2 update is now available. That includes version 1.0.6 on all platforms, and the 1.0.6.1 hotfix on PC.]