Discharge

You touch the creature and send a powerful charge of electricity into it. Make a melee spell attack against the target. You have advantage on the attack roll if the target is wearing a metal armor or it is a construct. On a hit, the target takes 8d8 lightning damage, and is pushed 15 feet away from you. Creature must make a Constitution saving throw. On a failed save, a creature can't take reactions until the start of its next turn and fall prone, if target is wearing a metal armor or it is a construct, it will get disadvantage on this saving throw.

At Higher Levels. When you cast this spell using a spell slot of 5th level or higher, the damage increases by 1d8 for each slot level above 4th.

[Tome of spells: Lightning]