Accessories are powerful and awesome looking hats, wings, backpacks, and more. They help you stand out in-game and allow you to show off cool achievements. Most accessories also come with boosters for Jobs and Artifacts.
In spawn, you can find the Wardrobe Building. Here you can purchase a selection of accessories directly from the merchant with in-game money. The merchant's collection changes every day. Accessories can also be found in crates, from minigames, and other activities.
In the same building you can also enter the Wardrobe itself. This allows you to preview how every accessory item looks on your character, as can be seen in the video below.
Equip your unlocked accessories by going into /wardrobe. This command can be accessed from anywhere. If you instead wish to equip other cosmetics, such as particle effects, you can go into /cosmetics.