Place it at the peak of a horror edit, after a slow build and just before the reveal lands. Follow it with the FNAF jumpscare scream for a second hit, then cut straight to black for the strongest finish.
About this sound
This is a roughly four-second jumpscare clip centred on Endo, the animatronic endoskeleton. It delivers a sudden shock that feels startling and tense, turning a quiet moment into an uneasy one in an instant. The clip comes from TJOC: SM, where Endo appears as a jumpscare threat.