Put it right after the gunfire in a death clip, with the Fortnite Pump Shotgun Sound just before it to show the hit, then follow it with the Roblox Oof Sound as a second, smaller reaction to the same death.
About this sound
This 2.4-second clip is a single gruff Russian shout from a S.T.A.L.K.E.R. bandit, complaining in slang that he has just caught a bullet. The rough, fast delivery makes the pain sound absurd and darkly funny rather than serious, so it lands as an instant reaction to bad luck. It comes from those games, where the line is spoken after a bandit is shot.