This challenge is part of Fortnite Season 3 Week 5 Challenges and you'll have to upgrade a weapon in Salty Springs. The question here will be where is the upgrading workbench, which is essential to craft your new arsenal.
Map
You'll find a "fixed" improvement workbench in the garage of the northernmost house on the ground floor. Any kind of improvement will be enough to complete the challenge. Important: we're not talking about weapon swapping here, we're talking about improvement. Transforming a grey quality weapon into a green one will only cost you 10 units of each material.
Salty Springs is a place that's already a hotly contested place in normal times. This challenge is only going to make it worse, and it may be difficult to accomplish this challenge from the moment you land.
We recommend you land a little more on the outskirts, then wait for the first or second storm circle to sneak into town and upgrade your weapon. Rest assured, upgrade workbenches are totally indestructible!
You can also use the portable upgrade workbenches that have been added, which also allow you to complete the challenge.
Original content by Romain "Zorg" Becquelin.