This guide will let you know how to unlock the Blackmarket in Roblox The Wild West.
First, you are going to need a key. Spawn at the howling peak and head to the Auction center.
Now you can purchase a key here.
Once you get your key spawn at Puerto Dorado.
You will need to head to the general store.
Now go to this place and open the door. You can talk to a guy there who will give you access to the shop.