Enum.Keycode is mostly used for detecting when a player presses a key on their keyboard. Here's an example:

(This is a client script that can be put in StarterGui or StarterPlayerScripts, your choice.)
local key = game:GetService("UserInputService")

local tool = Instance.new("Tool")

key.InputBegan:Connect(function(input)

      if input.Keycode == Enum.Keycode.E then

            tool.Name = "YourCustomName"

            tool.Parent = game.Players.LocalPlayer.Backpack

      end

end)

if tool.Parent == game.Players.LocalPlayer.Backpack then

      script:Destroy()

end

This will give a tool to a player when E is pressed. The script after it will prevent duplicate tools being given. You can retrieve the script after the player's death from another script.