How do I clone my tool to a backpack?

The backpack always resets when the player's character loads, consider using it on the CharacterAdded signal.

local ReplicatedStorage = game:GetService("ReplicatedStorage")

local BlueKeyCard = ReplicatedStorage:WaitForChild("BlueKeyCard")
local YellowKeyCard = ReplicatedStorage:WaitForChild("YellowKeyCard")

local function OnPlayerAdded(player)
    print(string.format("%s has joined the server!", player.Name))
    player.CharacterAdded:Connect(function(Character)
        local Backpack
        repeat
            wait() 
        until player:FindFirstChildWhichIsA("Backpack")
        Backpack = player:FindFirstChildWhichIsA("Backpack")
        local Rank = player:GetRankInGroup(7495829)
        if Rank == 255 then
            local success, response = pcall(function()
                YellowKeyCard:Clone().Parent = Backpack
            end)
            if success == true then
                return print(string.format("Keycard was given to %s", player.Name))
            else
                return error(response)
            end
        elseif Rank == 19 then
            local success, response = pcall(function()
                BlueKeyCard:Clone().Parent = Backpack
            end)
            if success == true then
                return print(string.format("Keycard was given to %s", player.Name))
            else
                return error(response)
            end
        end
    end)
end

I fixed it, my script is basic not too advanced because im still a beginner here's the script anyways:

--Script made by WINDOWS10XPRO

--[[
    Title: KeyCardManagerScript
    Goal: Gives keycard to specific rank in a group when they join the  server
    Description: This script is made by WINDOWS10XPRO. It's an open source.     You can copy it if you want to.
]]--

--Variables:

local GroupID = 7495829 -- Your GroupID here
local ReplicatedStorage = game:GetService("ReplicatedStorage") -- ReplicatedStorage
local BlueKeyCard = ReplicatedStorage.BlueKeyCard -- Your Item
local YellowKeyCard = ReplicatedStorage.YellowKeyCard -- Your Item

--Ranks:
local Chairman = 255 -- Your rank number here
local President = 19 -- Your rank number here

--Scripts:

game.Players.PlayerAdded:Connect(function(Player) -- This line checks if a player has joined the server, and player is an argument.
    Player.CharacterAdded:Connect(function(Character)
        print(Player.Name .. " Has Joined The Server") -- Printing out the player's name in the Developer Console, press F9 if you're on pc.
        if Player:GetRankInGroup(GroupID) == President then -- Checks if the player's rank is President
            wait(1)
            local YellowKeyCardClone = YellowKeyCard:Clone() -- Set a variable to clone the keycard
            YellowKeyCardClone.Parent = Player:WaitForChild("Backpack") -- Set the keycard parent to the player's backpack
            local CheckKeyCardInBackpack = Player:WaitForChild("Backpack"):FindFirstChild("YellowKeyCardClone") -- Checks if the keycard is in the backpack
            wait(8)
            if CheckKeyCardInBackpack then -- If there is a keycard then it's successfully added 
                print("Succesfully added!")
            elseif not CheckKeyCardInBackpack then
                print("Cloning failed!") -- else it's not but for some reason it says cloning failed but it actually success
            end
            if Character.Humanoid.Health == 0 then
                wait(4.75)
                YellowKeyCardClone.Parent = Player:WaitForChild("Backpack") -- I was forced to do this ;-; bruh
            end

        elseif Player:GetRankInGroup(GroupID) == Chairman then -- Checks if the player's rank is Chairman
            wait(1)
            local BlueKeyCardClone = BlueKeyCard:Clone() -- Set a variable to clone the keycard
            BlueKeyCardClone.Parent = Player:WaitForChild("Backpack")
            local CheckKeyCardInBackpack = Player:WaitForChild("Backpack"):FindFirstChild("BlueKeyCardClone")
            wait(8)
            if CheckKeyCardInBackpack then
                print("Succesfully added!")
            elseif not CheckKeyCardInBackpack then
                print("Cloning failed!")
            end
            if Character.Humanoid.Health == 0 then
                wait(4.75)
                BlueKeyCardClone.Parent = Player:WaitForChild("Backpack") -- I was forced to do this ;-; bruh
            end
        else
            print("Did not join the group or doesn't met the group's rank requirement.")
        end
    end)
end)

you need to use CharacterAdded

it's at line 36. Hope this helps :D