What can I do?

I know this this can only work on LocalScripts, but what can I do to make it when a player touches the part, and then presses the letter to activate the other part?

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

script.Parent.Touched:connect(function(hit)
	mouse.KeyDown:connect(function(Key)
		if Key == "f" then
			game.Workspace.TestDoor.Transparency = 1
		end
	end)
end)

Your program isn't running because you're putting a local script in a part. Local scripts only work inside the starter Gui, or starter pack.