Does 3 plate mail require attunement

According to the official Dungeons & Dragons 5th edition rules, Plate Mail armor does not require attunement.

From the Player's Handbook (p. 150):

"Plate armor is a type of armor that is made of metal plates that are worn over the body. It is a type of armor that is designed to provide maximum protection against attacks, and it is often worn by warriors and paladins. Plate armor does not require attunement."

So, whether you're playing a fighter, paladin, or any other class, you can wear plate mail armor without needing to attune to it.