A script meant to launch a fireball isn't working, but no errors appear when i run it?

I'm making a game where if you press 'F' you launch a fireball. This is the script i'm using

game.Players.PlayerAdded:wait()
Player = script.Parent.Parent.Parent -- Gets LocalPlayer 

Player.CharacterAdded:wait()
Character = Player.Character

Mouse = Player:GetMouse()

function onKeyDown(key) 
	if key:lower() == "f" then 
		local ball = Instance.new("Part") 
		ball.TopSurface = "Smooth" 
		ball.BottomSurface = "Smooth" 
		ball.Shape = "Ball" 
		ball.Transparency = 0.7
		ball.BrickColor = BrickColor.new("Bright red") 
		ball.Parent = game.Workspace 
		
		local fire = Instance.new("Fire") 
		fire.Parent = ball 
		fire.Size = 12 
		fire.Heat = 0 
		fire.Color = BrickColor.new("Really black")
		
		local velocity = Instance.new("BodyVelocity") 
		velocity.maxForce = Vector3.new(999, 999, 999)
		velocity.velocity = Character.Head.CFrame.lookVector * 50
		velocity.Parent = ball  
		
		ball.Position = Character.Head.Position + 2
		ball.CFrame = Character.Head.CFrame * CFrame.new(0, 0, 10)
	end 
end 

Mouse.KeyDown:connect(onKeyDown)
-- this is placed in a tool inside the starter pack

it doesn't show any errors when i run it, but it doesn't work Can anyone explain what the problem is? I'm pretty new to roblox lua scripting, so sorry if this is a stupid question