PHB
Magic Weapon
2-level Transmutation
Casting Time: 1 bonus action
Range/Area: Touch
Components: V, S
Duration: Concentration, 1 hour
You touch a nonmagical weapon. Until the spell ends, that weapon becomes a magic weapon with a +1 bonus to attack rolls and damage rolls.
At higher levels: When you cast this spell using a spell slot of 4th level or higher, the bonus increases to +2. When you use a spell slot of 6th level or higher, the bonus increases to +3.