Bellow

You shout a thunderous phrase that bursts outward from your location. Each creature in a 20-foot cone originating from you must make a Constitution saving throw. A creature takes 4d8 thunder damage and is pushed 15 feet away from you on a failed save, or half as much damage and is not pushed on a success.

At higher levels: When you cast this spell using a spell slot of 4th level or higher, the damage increases by 1d8 for each slot level above 3rd.