How to fix this Code GUI?

I do not know how to fix this GUI, whenever I enter a code in the script "Codes" it just shows "Submitting". It is not printing what it is supposed to be printing in output either.

local codes = require(game.ServerStorage.Codes)

local usedCodes = game:GetService("DataStoreService"):GetDataStore("UsedCodes")

local function IsInTable(t, thing)
	for i, v in pairs(t) do
		if v == thing then
			return(true)
		end
	end
	return(false)
end

game.Players.PlayerAdded:connect(function(player)
	if player.userId > 0 then
		local pCodes = usedCodes:GetAsync("user_" .. player.userId)
		if not pCodes then
			usedCodes:SetAsync("user_" .. player.userId, {})
		end
	end
end)

function game.ReplicatedStorage.RedeemCode.OnServerInvoke(player, code)
	if player.userId > 0 then
		code = string.lower(code)
		if codes[code] then
			local pCodes = usedCodes:GetAsync("user_" .. player.userId)
			if pCodes then
				if not IsInTable(pCodes, code) then
					table.insert(pCodes, code)
					usedCodes:SetAsync("user_" .. player.userId, pCodes)
					codes[code](player)
					return true, "Success!"
				else
					return false, "You've already redeemed that code."
				end
			end
		else
			return false, "Invalid code."
		end
	end
	return false, "Sorry, guests can't redeem codes."
end

Script with Codes (ServerStorage):

local codes = {
	["supercode"] = function(player)
		print(player.Name .. " entered a code!")
	end,
	["examplecode"] = function(player)
		print("this example code was redeemed by " .. player.Name)
	end,
	["mlg_swag_360"] = function(player)
		print(player.Name .. " is mlg!!!1!11!")
	end
	
	["test"] = function(player)
		print("this example code was redeemed by " .. player.Name)
	end,
}

return(codes)