Electrocute

A massive arc of lightning leaps from your hand to a target you can see within range. The target must make a Constitution saving throw. On a failed save, the target takes 4d12 lightning damage and is stunned until the start of your next turn. On a successful save, the target takes half as much damage and isn't stunned.

At Higher Levels: When you cast this spell using a spell slot of 4th level or higher, the damage increases by 1d12 for each slot level above 3rd.

Source: Kibble's Generic Elemental Spells