Advanced Alchemist's Fire

You have mastered the ability to quickly mix and launch a sticky, adhesive fluid that ignites when exposed to air. Make a ranged spell attack against a creature or object that is not currently under the effects of this spell. On a hit, the target takes 1d4 fire damage. At the start of each of its turns for the duration of the spell the target takes an addition 1d4 fire damage. A creature can end this damage early by using its action or bonus action to make a Dexterity saving throw against your Spell Save DC to extinguish the flames.

The spell’s initial damage (not the ongoing damage) increases by 1d4 when you reach 5th level (2d4), 11th level (3d4), and 17th level (4d4).