pf2e.fyi
From Pathfinder #213: Thirst for Blood, which isn't enabled.

Transfusion

FEAT 8
ARCHETYPE
Activity 2 actions
Archetype Sanguimancer
Prerequisites Sanguimancer Dedication
Cost 5 or more sanguimancy Hit Points

You bring forth the regenerative properties of blood on behalf of an ally or yourself. You touch a willing creature and grant them fast healing 1 for 5 rounds. You can spend an additional 5 sanguimancy Hit Points to increase the fast healing by 1, to a maximum of 8.

Pathfinder #213: Thirst for BloodORC