Dragonbolt

A bolt of draconic lightning strikes a non-magical weapon within 15 ft of you, coating it in a crackling electric energy. Until the spell ends, that weapon becomes a magic weapon with a +1 bonus to attack rolls and damage rolls, its damage type also changes to Lightning.

Using a Higher-Level Spell Slot. The bonus changes to +2 at spell slot level 4 or higher, and +3 at spell slot level 6 or higher.