Server Script, Code System

local DataStoreService = game:GetService("DataStoreService")
local DataKey = "DataCode_1:"

local rep = game:GetService("ReplicatedStorage")
local remote = rep:WaitForChild("RedeemCode")

local Codes = {"Test Code 1", "Test Code 2", "Test Code 3"}

remote.OnServerInvoke = function(Player, CodeSent)
    if table.find(Codes,CodeSent) then
        local Data = DataStoreService:GetDataStore(DataKey..CodeSent)
        local boolean,IsRedeemed = pcall(function()
            local toReturn = Data:GetAsync(Player.UserId) or false
            return toReturn
        end)

        if boolean == true then
            if IsRedeemed == false then
                Data:SetAsync(Player.UserId,true)
                -- code here, like for example give the player something if they have something in their leader stats like coins

                return true,"Code Received, Redeemed: "..CodeSent
            else
                return false,"Code Received, Already Redeemed: "..CodeSent
            end
        else
            return false,"Failed To Receive Code: "..CodeSent
        end
    else
        return false,"Invalid Code: "..CodeSent
    end
end