pf2e.fyi
From Pathfinder Secrets of Magic, which isn't enabled.

Fiery Retort

FEAT 8
DRUIDFIRE
Activity reaction
Prerequisites flame order
Trigger An opponent adjacent to you hits you with a melee weapon or a melee unarmed attack.
Frequency once per minute

Ignoring your pain, you sear your attacker with a wave of flame. The triggering opponent takes fire damage equal to your level.

Pathfinder Secrets of MagicOGL