How to Make already have item object?

Hello, I would like to know how do I remove clones from the tool in the backpack, for example, once I already have the item, when I click to buy an object it is cloning in the back pack. Could someone help me?

function buy()
	if script.Parent.Parent.Parent.Parent.Parent.Parent.leaderstats.Level.Value >= 45000 then
script.Parent.Parent.Parent.Parent.Parent.Parent.leaderstats.Level.Value = script.Parent.Parent.Parent.Parent.Parent.Parent.leaderstats.Level.Value-0
		local clone1 = game.ServerStorage.Sword:Clone()
		clone1.Parent = script.Parent.Parent.Parent.Parent.Parent.Parent.Backpack
	end
	end
	
script.Parent.MouseButton1Down:connect(buy)

It would really help if you used variables as mentioned above, making your code readable.

What you want to do to prevent multiple clones, is to use a debounce and a for loop to iterate through the player's backpack to see if the "Sword" already exists.

local player = game.Players.LocalPlayer
local Backpack = player:FindFirstChild("Backpack")
local Item = game:GetService("ServerStorage").Sword
local debounce = false -- Local debounce variable

script.Parent.TextButton.MouseButton1Click:Connect(function()
	if debounce == false then -- Only runs if debounce is false
		Item:Clone().Parent = Backpack 
	end
	
	for i,v in pairs(Backpack:GetChildren()) do -- For loop through children of backpack
		if v.Name == "Sword" then -- Check to see if there's an item called Sword
			debounce = true -- Debounce set to true, so the above code wouldn't run
		end
	end
end)

Well, I am going to provide you a solution with what almost everyone said. It is like looping through every item in your backpack.

function buy()

local var = script.Parent.Parent.Parent.Parent.Parent.Parent -- Creating a variable for simplification

local PlayerBackpack = var.Backpack:GetChildren() -- Creates a table with contents of the backpack

	if var.leaderstats.Level.Value >= 45000 then

		for i, tool in pairs(PlayerBackpack) do -- Runs a loopin the table created above
			if tool:IsA("Tool") then -- Checks if the item is a Tool then
				if tool.Name == "Sword" then -- Checks if the tool's name is Sword (eg)
					var.leaderstats.Level.Value =  var.leaderstats.Level.Value - 0
        				local clone1 = game.ServerStorage.Sword:Clone()
       					clone1.Parent = var.Backpack
				end
			end
		end

		
   	 end
    end

script.Parent.MouseButton1Down:Connect(buy) -- Make sure Capital 'C'

Lemme know if it helps!