The alert comes from Fortnite, the Epic Games shooter that became a cultural hit after Battle Royale launched in 2017, where players can send and accept friend requests from the lobby and in-game menus. Clips of streamers reacting to unexpected requests helped the short notification travel beyond the game itself, and it is now reused as a shorthand for any incoming request, invite, or message in edited videos. Its staying power comes from that instant recognition among Fortnite players, who hear the cue and immediately know what kind of social interruption has just arrived.