Erupting Flame

You cause fire to erupt from three points in the ground you can see within range. Choose three 5-foot squares. A creature completely or partially in that square must succeed a dexterity saving throw or take 7 (2d6) fire damage or half as much on a successful save. If a creature fails its saving throw it takes 3 (1d6) fire damage at the start of each of its turns for the duration or until it or another creature uses an action to extinguish the flames

The fire ignites any flammable objects in the squares that aren't being worn or carried.

At Higher Levels. When you cast this spell using a spell slot of 3rd level or higher, the initial damage increases by 1d6 for each slot level above 1st.