tModLoader How do I make a Modded Item drop from a Vanilla Treasure bag?

[jaractus]

Hi, I'm trying to make a item drop from the Moon Lord Treasure bag, but I don't know how. It's a vanity item.
I've tried looking it up, but the most I found was tutorials on how to make a Modded Treasure Bag.

(If you need the code, tell me)

Thanks!