this is a script located in a tool, and once it is activated it defines the player (plr) and I use the plr for the argument in the fireclient. But the console output says that I need a player object, but I have no idea what that means.
As polysaccharide said, the Tool.Activated event doesn’t give any parameters. Try getting the player like this: local player = game.Players:GetPlayerFromCharacter(script:FindFirstAncestorOfClass("Model"))