[HELP] Stop Players from picking up Tools?

So i got this Backpack Gui, it creates slots (10) where tools go, when a Player picks them up. My Problem now is that if a player has 11 Tools and he drops one of those 10, which are shown, the 11 tool is just gone. it isnt going automaticly in the missing Slot. I just cant access the 11 Tool.

Any way to put the tool automaticly in the missing field? or stop the players from picking up Tools, when he is full (10 tools)?

game:GetService('StarterGui'):SetCoreGuiEnabled(Enum.CoreGuiType.Backpack, false)
 
 --< variables >--
local uis = game:GetService("UserInputService")
local player = game.Players.LocalPlayer
local char = workspace:WaitForChild(player.Name) -- added WaitForChild
local bp = player.Backpack
local hum = char:WaitForChild("Humanoid")
local frame = script.Parent.Frame
local template = frame.Template
local equipped = 0.7 -- icon transparencies
local unequipped = 0.2

local iconSize = template.Size
local iconBorder = {x = 15, y = 5} -- pixel space between icons

local inputKeys = { -- dictionary for effective referencing
	["One"] = {txt = "1"},
	["Two"] = {txt = "2"},
	["Three"] = {txt = "3"},
	["Four"] = {txt = "4"},
	["Five"] = {txt = "5"},
	["Six"] = {txt = "6"},
	["Seven"] = {txt = "7"},
	["Eight"] = {txt = "8"},
	["Nine"] = {txt = "9"},
	["Zero"] = {txt = "0"},
}

local inputOrder = { -- array for storing the order of the keys
	inputKeys["One"],inputKeys["Two"],inputKeys["Three"],inputKeys["Four"],inputKeys["Five"],
	inputKeys["Six"],inputKeys["Seven"],inputKeys["Eight"],inputKeys["Nine"],inputKeys["Zero"],
}
	
--< functions >--
function handleEquip(tool)
	if tool then
		if tool.Parent ~= char then
			hum:EquipTool(tool)
		else
			hum:UnequipTools()
		end
	end
end

function create() -- creates all the icons at once (and will only run once)

	local toShow = #inputOrder -- # operator can only be used with an array, not a dictionary
	local totalX = (toShow*iconSize.X.Offset)+((toShow+1)*iconBorder.x)
	local totalY = iconSize.Y.Offset + (2*iconBorder.y)
	
	frame.Size = UDim2.new(0, totalX, 0, totalY)
	frame.Position = UDim2.new(0.5, -(totalX/2), 1, -(totalY+(iconBorder.y*2)))
	frame.Visible = true -- just in case!

	for i = 1, #inputOrder do
		
		local value = inputOrder[i]		
		local clone = template:Clone()
		clone.Parent = frame
		clone.Label.Text = value["txt"]
		clone.Name = value["txt"]
		clone.Visible = true
		clone.Position = UDim2.new(0, (i-1)*(iconSize.X.Offset)+(iconBorder.x*i), 0, iconBorder.y)
		clone.ImageTransparency = unequipped
		
		local tool = value["tool"]
		if tool then
			clone.Tool.Image = tool.TextureId
		end

		clone.Tool.MouseButton1Down:Connect(function() -- click icon to equip/unequip
			for key, value in pairs(inputKeys) do
				if value["txt"] == clone.Name then
					handleEquip(value["tool"]) 
				end 
			end
		end)

	end	
	template:Destroy()
end

function setup() -- sets up all the tools already in the backpack (and will only run once)
	local tools = bp:GetChildren()
	for i = 1, #tools do 
		if tools[i]:IsA("Tool") then -- does not assume that all objects in the backpack will be a tool (2.11.18)
		for i = 1, #inputOrder do
			local value = inputOrder[i]
			if not value["tool"] then -- if the tool slot is free...
				value["tool"] = tools[i]	
				break -- stop searching for a free slot
			end
		end
		end
	end
	create()
end

function adjust()
	for key, value in pairs(inputKeys) do
		local tool = value["tool"]
		local icon = frame:FindFirstChild(value["txt"])
		if tool then
			icon.Tool.Image = tool.TextureId
			if tool.Parent == char then -- if the tool is equipped...
				icon.ImageTransparency = equipped
			else
				icon.ImageTransparency = unequipped
			end
		else
			icon.Tool.Image = ""
			icon.ImageTransparency = unequipped
		end
	end
end

function onKeyPress(inputObject) -- press keys to equip/unequip
	local key = inputObject.KeyCode.Name
	local value = inputKeys[key]
	if value and uis:GetFocusedTextBox() == nil then -- don't equip/unequip while typing in text box
		handleEquip(value["tool"])
	end 
end

function handleAddition(adding)

	if adding:IsA("Tool") then
		local new = true

		for key, value in pairs(inputKeys) do
			local tool = value["tool"]
			if tool then
				if tool == adding then
					new = false
				end
			end
		end

		if new then
			for i = 1, #inputOrder do
				local tool = inputOrder[i]["tool"]
				if not tool then -- if the tool slot is free...
					inputOrder[i]["tool"] = adding
					break
				end
			end
		end

	adjust()
	end
end

function handleRemoval(removing) 
	if removing:IsA("Tool") then
		if removing.Parent ~= char and removing.Parent ~= bp then

			for i = 1, #inputOrder do
				if inputOrder[i]["tool"] == removing then
					inputOrder[i]["tool"] = nil
					break
				end
			end
		end

		adjust()
	end
end

--< events >--
uis.InputBegan:Connect(onKeyPress)

char.ChildAdded:Connect(handleAddition)
char.ChildRemoved:Connect(handleRemoval)

bp.ChildAdded:Connect(handleAddition)
bp.ChildRemoved:Connect(handleRemoval)

--< start >--
setup()