From Pathfinder Lost Omens Draconic Codex, which isn't enabled.

Reactive Resilience

FEAT 8

ARCHETYPE

Activity reaction

Archetype Draconic Acolyte

Prerequisites Draconic Resilience

Frequency once per day

Trigger You take damage.

Requirements You are Channeling Draconic Essence.

Your power blunts blades and weakens spells like the hardiest of dragon scales. You gain resistance to the triggering damage equal to your level. Channel Draconic Essence ends.

Pathfinder Lost Omens Draconic CodexORC