How would I make a Leaderboard tab?

So I want a leaderboard to pop up when someone presses a certain button lets say.. T So What I want is that when someone is playing they can quickly access the leaderboard then have it quickly go away when they stop pressing the button. How would I do this?

Press Tab on your keyboard and it pops up. ROBLOX put that in.

Roblox already allows you to view the leaderboard by pressing tab to open and close the leaderboard

Well, Do you mean the leaderboard roblox has or a GUi leader Board?

Use this in a LocalScript.

local mouse = game.Players.LocalPlayer:GetMouse()
local key = "t" -- change this
local leaderboard = game.Players.LocalPlayer.PlayerGui.Leaderboard -- change this too

mouse.KeyDown:connect(function(k)
	if k:lower() == key:lower() then
		leaderboard.Visible = true
	end
end)

mouse.KeyUp:connect(function(k)
	if k:lower() == key:lower() then
		leaderboard.Visible = false
	end
end)