pf2e.fyi
From Pathfinder Guns & Gears, which isn't enabled.

Exploit Opening

FEAT 6
Activity reaction
Archetype Sniping Duo

Trigger Your spotter critically succeeds at a Strike against a creature, and that creature is within your crossbow or firearm's first range increment.

You take advantage of your spotter's devastating attack to unleash your own follow-up attack. Make a ranged Strike with a +2 circumstance bonus using a loaded crossbow or firearm against the target of the triggering attack.

Pathfinder Guns & GearsORC