How to Get the Memento Backpack in The Division 2

How to Obtain the Memento Backpack
Targeted Loot for Backpacks: You can farm Memento by targeting loot in areas that provide specific loot for backpacks.
World Activities: Completing various world activities (control points, missions, etc.) may also reward you with this exotic item.
Farm High Difficulty Missions: Engage in high-difficulty missions with directives enabled to increase your chances of obtaining the Memento Backpack.

How to Increase Your Chances of Getting the Memento Backpack
Farm Boss Floors: Complete boss floors in The Summit or similar high-level content on the highest difficulty with a full team. This maximizes the chances of acquiring Memento.
Team Efforts: Farm together with your team to improve the chances of getting the backpack, as everyone can share the loot.
Memento Backpack Talent: Kill Confirmed The Memento Backpack has the talent "Kill Confirmed", which grants bonuses for each enemy you defeat. Enemies you kill drop a trophy that provides short and long-term buffs. The short-term buff scales with the number of core attributes equipped, and lasts 10 seconds.
+5% Weapon Damage per Weapon Damage Core
+10% Bonus Armor per Armor Core
+5% Skill Efficiency per Skill Core
For every trophy you collect, gain an additional:
+1% Weapon Damage
+1% Skill Efficiency
+0.1% Armor Regeneration for 300 seconds (5 minutes).
Maximum Stacks: 30
Memento Mask Stats
The Memento Mask has the following stats:
Main Stat: Blue (Armor)
Stat #1: Weapon Damage
Stat #2: 1 Skill tier.

Best Build for the Memento Mask
To maximize the Memento Mask's potential, it is recommended to focus on a build that emphasizes survivability and aggressive damage dealing. Use weapons with high critical damage and health to fully leverage the Memento Mask’s bonuses.