Is a $3 bill real?

Excuse me, could you clarify something for me? I've heard rumors about the existence of a $3 bill, but I'm not sure if it's legitimate or not. Is a $3 bill actually real and in circulation, or is it just a myth or a novelty item? I'm interested in learning more about the history and authenticity of this type of currency, if it indeed exists. Thank you for your help in clarifying this matter.