Roblox allows players to freely personalize clothing items, allowing them to express themselves and stand out from others.

Before designing a shirt, you need to have a Roblox account and some Robux, the in-game currency used by players to buy accessories, clothes, and skins from the avatar shop.

Roblox has a huge playerbase but there are more than enough codes to spare as of April 2021, so here's a list of the active ones.

The Roblox team discusses how the additions point to where Roblox is starting to flex across platforms, into VR, and eventually maybe AR too.