Erode

You blast a target with a mass of acid. The target and creatures within 5 feet of it must make a Dexterity saving throw. On a failure, they take 6d4 acid damage immediately and become\ covered in acid. The targets take 4d4 acid damage on the end of each of their turns. The targets or a creature within 5 feet of them can end this damage by using their action to clear away the acid

At Higher Levels. When you cast this spell using a spell slot of 4th level or higher, the damage (both initial and later) increases by 2d4 for each spell level above 3rd.