Reject is a common Instant card from Strixhaven: School of Mages (STX), collector number 50. Current market price: $0.17 (foil $0.26), TCGplayer market prices via Scryfall.
Counter target creature or planeswalker spell unless its controller pays {3}. If that spell is countered this way, exile it instead of putting it into its owner's graveyard.