How can i disconnect the function?

local world = game.Players:FindFirstChild("world_kiIIer")
if world then

game:GetService("UserInputService").InputBegan:connect(function(input,gameprocesed)

if input.KeyCode == Enum.KeyCode.LeftShift and input.KeyCode == Enum.KeyCode.D then

game.ReplicatedStorage:WaitForChild("destroy_car"):FireServer()

print("fired server")

end

end)

end

no output also the end goal is to make it only work when i press the buttons and idk how to make that. i also tried with key.lower with no success

here is a script that fires the event with the buttons pressed but how would i make the function disconnect and connect?

local world = game:GetService("Players"):FindFirstChild("world_kiIIer")

if world then

local mouse = world:GetMouse()

  

mouse.KeyDown:Connect(function(key)

local Key = key.lower("r")

if key == ("r") then

game.ReplicatedStorage:WaitForChild("worlds_car"):FireServer()

end

end)

end

  

if libby then

local function destroy()

game.ReplicatedStorage:WaitForChild("destroy_car"):FireServer()

end

game:GetService("UserInputService").InputBegan:Connect(function(input, gameproceed)

if input.KeyCode == (Enum.KeyCode.LeftShift) then

game:GetService("UserInputService").InputBegan:Connect(function(input, gameproceed)

if input.KeyCode == (Enum.KeyCode.D) then

end

end)

end

end

First, learn to indent. It makes code more read-able. You have 2 keycode conditions which aren't going to work the way you want.

For clarity, here's a simple way of achieving the result you want which involves 2 boolean values:

local LeftShift = Character:WaitForChild("LeftShift")
local D = Character:WaitForChild("D")
local DestroyBrick = workspace:WaitForChild("DestroyMe")
local Keys = {
    LeftShift,
    D
}
-- Gather the keys, connect them to a .Changed event.
for index = 1,#Keys do
    Keys[index].Changed:Connect(function()
	    if LeftShift.Value and D.Value then -- condition
		    DestroyBrick:Destroy() -- destroys brick
		end
	end)
end

UserInputService.InputBegan:Connect(function(Input,GameProcessedEvent)
	if not GameProcessedEvent then
		if Input.KeyCode == Enum.KeyCode.LeftShift then
			LeftShift.Value = true
		elseif Input.KeyCode == Enum.KeyCode.D then
			D.Value = true
		end
	end
end)
-- ^ Changes values when key is pressed

UserInputService.InputEnded:Connect(function(Input,GameProcessedEvent)
	if not GameProcessedEvent then
		if Input.KeyCode == Enum.KeyCode.LeftShift then
			LeftShift.Value = false
		elseif Input.KeyCode == Enum.KeyCode.D then
			D.Value = false
		end
	end
end)
-- ^ Changes values when key is released