Attempt to index nil with 'Backpack'

local give = eco:Clone()
give.Parent = player.Backpack -- here is error: Workspace.SCI.Screen.SurfaceGui.Script:53: attempt to index nil with 'Backpack'. 

Anyone know how to fix - its a normal script within a surfacegui in workspace.

Full Script
local startbtn = script.Parent.StartP.ImageButton

local Players = game:GetService("Players")

local part = workspace.SCI.playername

local ecobtn = script.Parent.Select.ecobtn

local ecosbtn = script.Parent.Select.ecosbtn

local ecopbtn = script.Parent.Select.ecopbtn

local business = script.Parent.Select.Business

local eco = game.ServerStorage.Tickets:WaitForChild("Eco Boarding Pass")

local ecos = game.ServerStorage.Tickets["Strech  Boarding Pass"]

local ecop = game.ServerStorage.Tickets["Premium Eco Boarding Pass"]

local bus = game.ServerStorage.Tickets["Business Boarding Pass"]

---


part.Touched:Connect(function(hit)
	local player = Players:GetPlayerFromCharacter(hit.Parent)
	if player then
		_G.name = player.Name
	end
end)

local function start() -- bug here
	script.Parent.Parent.Parent.Collide.CanCollide = true
	script.Parent.StartP.Visible = false
	script.Parent.loadingscreen.Visible = true
	wait(3)
	script.Parent.loadingscreen.Visible = false
	script.Parent.Select.TextLabel.Text = _G.name
	script.Parent.Select.Visible = true
	script.Parent.Select.ecobtn.MouseButton1Click:Connect(function(player)
		local ecoremotevent = game.ReplicatedStorage.SCIEvents.EconomyClickEvent
		script.Parent.Select.Visible = false
		script.Parent.Printing.Visible = true
		local give = eco:Clone()
		give.Parent = player.Backpack -- here is error: Workspace.SCI.Screen.SurfaceGui.Script:53: attempt to index nil with 'Backpack'. 
		wait(4)
		script.Parent.Parent.Parent.Collide.CanCollide = false
		script.Parent.Printing.Visible = false
		local endscreen = script.Parent.endscreen
		endscreen.Visible = true
		wait(5)	
		endscreen.Visible = false
		script.Parent.StartP.Visible = true
	end)	

end

---

startbtn.MouseButton1Down:Connect(start)

TextButton.MouseButton1Click doesn’t pass a player as a parameter.