Why wont this keybind function at all?

I am making a script that assigns a keybind to an ability depending on what you put in a certain textbox. The way it works is it has a StringValue inside of a button along with a textbox, and when something is put into the textbox, it saves to the StringValue I can't seem to figure out how to incorporate it with UserInputService though.

When you enter text, KeyBind becomes that text. (Would also appreciate it if someone knows how to cut off all the letters so only the first inputted word remains)

script.Parent.FocusLost:Connect(function()
       --Key is the StringValue, script.Parent is the textbox
	script.Parent.Parent.Key.Value = script.Parent.Text
end)

Script That Receives KeyBind

local Player = script.Parent.Parent
local mouse = Player:GetMouse()
local debounce = false
local UIS = game:GetService("UserInputService")
local keybind = string.lower(Player.PlayerGui.Skills.Frame.Jump.Key.Value) or string.upper(Player.PlayerGui.Skills.Frame.Jump.Key.Value) 
UIS.InputBegan:Connect(function(key) --I think ??? below is the potential problem
	if key.KeyCode == Enum.KeyCode.????? and debounce == false then
    debounce = true	
    local Key = "Jump"
    local char = Player.Character
    local hum = char.Humanoid 
    game.ReplicatedStorage.Moves:FireServer(mouse.hit,Key)
	wait(6)
	debounce = false
	end
	end)