How do i make this script so my inventory goes away the next time you press e?

THE OPENING PART IS WORKING Here is the script

--Ignore lines 1 to 9 thats the working part
--Opening part
local plr = game.Players.LocalPlayer
local mouse = plr:GetMouse()

mouse.KeyDown:connect(function(key)
    if key:lower() == "e" then
        plr.PlayerGui.Inventory.Main.Visible = true
    end
end)

--Closing part
mouse.KeyDown:connect(function(key)
	if plr.PlayerGui.Inventory.Main.Visible == true then
	if key:lower() == "e" then
		plr.PlayerGui.Inventory.Main.Visible = false
	   end	
	end
end)

No output appears

You can also simplify your script by using the "not" keyword.

local plr = game.Players.LocalPlayer
local mouse = plr:GetMouse()

mouse.KeyDown:connect(function(key)
    if key:lower() == "e" then
        plr:WaitForChild("PlayerGui").Inventory.Main.Visible = not plr:WaitForChild("PlayerGui").Inventory.Main.Visible --Sets the visibility of the GUI object to the opposite of what it is already, so false is true and true is false.
    end
end)

Gives you less lines in the script, and saves repeating the KeyDown event twice.