I'm making my own inventory system, player can't unequip tools properly?

I'm replacing roblox's inventory system with my custom made one and eveything is working out great except the problem is if you have a tool and you unequip the same key coordinated to that tool, you can't unequip that tool.

My system is where I have a full table list of what the player has in their backpack, and whenever the player presses a certain key, it converts that to a number that can index whatever tool inside of the player's backpack.

Here's the full script that makes up the inventory system:

-- // Services \\ -- 
local UserInputService = game:GetService("UserInputService")
local PlayersService = game:GetService("Players")

-- // Variables \\ --
local Player = PlayersService.LocalPlayer
local Character = Player.Character or Player.CharacterAdded:Wait()
local Humanoid  = Character:WaitForChild("Humanoid")
local Backpack = Player.Backpack -- Actual backpack containing what the gear the player has

local BackpackChildren = Backpack:GetChildren()
local Copy = BackpackChildren

-- // Tables & Statements \\ --

local KeyToNumber = {
    ["One"] = 1,
    ["Two"] = 2,
    ["Three"] = 3,
    ["Four"] = 4,
    ["Five"] = 5,
    ["Six"] = 6,
    ["Seven"] = 7,
    ["Eight"] = 8,
    ["Nine"] = 9,
    ["Zero"] = 0
}

-- // Functions \\ -- 

local function GetToolIndex(Tool, BackpackItems)
    for i,v in pairs(BackpackItems) do
        if v == Tool then
            return i
        end
    end
end

local function EquipTool(Index)
    if not Humanoid:FindFirstChildOfClass("Tool") then  -- if theres no tool equipped
        local Tool = BackpackChildren[Index]
        if Tool then
            Humanoid:EquipTool(Tool)
            return true
        end
    end
    return false    -- if theres a tool equipped
end

local function UnequipTool(Index) -- we know there's a tool equipped    
    Humanoid:UnequipTools()
--  Humanoid:EquipTool(BackpackChildren[Index])
end

local function InputStarted(Input, GameProcessedEvent)
    local Conversion = KeyToNumber[Input.KeyCode.Name]
    if Conversion then
        if not EquipTool(Conversion) then
            UnequipTool() -- if there is a tool equipped, we would want to unequip it
        end
    end
end


-- // Events \\ --
UserInputService.InputBegan:Connect(InputStarted)

If you would like a hands-on experience to what I'm saying, here's the link tot the place that showcases the system:

https://web.roblox.com/games/4718814317/Testing-Place-Teams

Use the system like how you would normally use for roblox's inventory system.