The Armorer was, you guessed it, an armorer. Specifically, she was a Mandalorian armorer for the Tribe in The Mandalorian. The Tribe was the same group Din Djarin belonged to. They believed a Mandalorian should never remove their helmet in front of anyone else. (This is the way.)
Emily Swallow played The Armorer. Lauren May Kim was Swallow’s stunt double.
Learn more about The Armorer on her Wookieepedia page.