You concentrate bolts of lightning on the tips of your fingers and shoot them at a creature within range. You make a ranged spell attack against the creature for 1D8 lightning damage. On a hit, the creature must make a CON saving throw. On a failed save they can't take reactions until then start of their next turn. 

At higher levels~ The spells damage increases by 1D8 when you reach 5th level (2D8), 11th level (3D8), and 17th level (4D8)