how do i fix 16:11:18.310 - er is not a valid member of PlayerGui ?

the error: 16:11:18.310 - er is not a valid member of PlayerGui

game.ReplicatedStorage.Transfromgold.UNDOTRANS.OnServerEvent:Connect(function(plr)


local chr = plr.Character
local hum = chr.Humanoid

        for _,none in pairs(hum:GetChildren()) do
            if none:IsA("NumberValue") then
                none:Remove()
            end
        end
        wait(.12)
local waited = plr.PlayerGui.er:WaitForChild("er")
                for _,kill in pairs(waited:GetChildren()) do
                    if kill:IsA("NumberValue") then
                    local copy = kill:Clone()
                    wait(.12)
                        copy.Parent = hum
                    end
                end


end)


end)

the firing script

local tem = "None"
local InputService = game:GetService("UserInputService")
InputService.InputBegan:Connect(function(input)


-- on 

    local key = input.KeyCode 
    if key == Enum.KeyCode.R then
    game.ReplicatedStorage.Transfromgold.Trans:FireServer()
   print("fired")
    end
end)
-----




InputService.InputBegan:Connect(function(input)

    local plr = game.Players.LocalPlayer
local chr = plr.Character
local hum = chr.Humanoid
    local key = input.KeyCode 
    if key == Enum.KeyCode.E then

    game.ReplicatedStorage.Transfromgold.UNDOTRANS:FireServer()
end
end)