Chandra's Regulator is a rare Legendary Artifact card from Core Set 2020 Promos (PM20), collector number 131p. Current market price: $0.41 (foil $0.60), TCGplayer market prices via Scryfall.
Whenever you activate a loyalty ability of a Chandra planeswalker, you may pay {1}. If you do, copy that ability. You may choose new targets for the copy. {1}, {T}, Discard a Mountain card or a red card: Draw a card.