All you need to do is play, once or more.. I guess.
The goal is shared between the whole community so you don’t need to do all the work.
Killers have to break 1,000,000 generators + pallets
Survivors have to drop 1,000,000 pallets
Completing this challenge will unlock the Dwearder and Marked Bolo Machete for the whole community! Completing each daily challenge will allow you to unlock the final anniversary challenge “It takes all 5” and its surprise rewards.