Can Someone help me fully understand the Update Async Datastore Method?

I have realized that Update Async is a lot better than Set Async and that it helps get rid of the "DataStore request was added to queue. If request queue fills, further requests will be dropped. Try sending fewer requests.Key = (some random id that I cant find)".

Here is the scripts that i'm working with:

Module script:

local Settings = {
	["Coins"] = {
		["parent"] = "Player",
		["obj"] = "IntValue",
		["val"]= 0,
	},
	["DeviceType"] = {
		["parent"] = "StatsFolder",
		["obj"] = "StringValue",
		["val"]= 0,
	},
	["CoinsMultilier"] = {
		["parent"] = "Multipliers",
		["obj"] = "IntValue",
		["val"]= 1,
	},
	["Seconds"] = {
		["parent"] = "TimePlayed",
		["obj"] = "IntValue",
		["val"]= 0,
	},
	["Minutes"] = {
		["parent"] = "TimePlayed",
		["obj"] = "IntValue",
		["val"]= 0,
	},
	["Hours"] = {
		["parent"] = "TimePlayed",
		["obj"] = "IntValue",
		["val"]= 0,
	},
	["Donations"] = {
		["parent"] = "StatsFolder",
		["obj"] = "IntValue",
		["val"]= 0,
	},
	["StagesCompleted"] = {
		["parent"] = "StatsFolder",
		["obj"] = "IntValue",
		["val"]= 0,
	},
	["TotalCoins"] = {
		["parent"] = "StatsFolder",
		["obj"] = "IntValue",
		["val"]= 0,
	},
}

return Settings

and the Main Leaderstats Script

local data = game:GetService("DataStoreService")
local datastore = data:GetDataStore("Code:000kaq")
local Settings = require(game.ReplicatedStorage.Modules.LeaderstatsSettings)

game.Players.PlayerAdded:Connect(function(plr)
	local prefix = plr.UserId

	local Stat = Instance.new("Folder",plr)
	Stat.Name = "StatsFolder"

	local multipliers = Instance.new("Folder", plr)
	multipliers.Name = "Multipliers"

	local timer = Instance.new("Folder",Stat)
	timer.Name = "TimePlayed"

	for i,v in pairs(Settings) do
		local where = v.parent --Where the datastore gets saved at
		if v.parent ~= "Player" then
			if plr:findFirstChild(v.parent) then--if the folder is already created then
				where = plr[v.parent]
			else
				local folder = Instance.new("Folder",plr) -- creates folder inside player
				folder.Name = v.parent -- sets the folder name

				where = folder -- this was the mistake

			end
		end

		if v.parent == "Player" then
			where = plr
		end
		--// Creates the Value
		local val = Instance.new(v.obj,where)
		val.Name = i -- // The name u did put on left side inside the Module
		val.Value = v.val --// How much if set
	end

	local Data = nil

	local success, err = pcall(function()
		Data = datastore:UpdateAsync(prefix, function(OldData)
			return 
		end)
	end)
end)

The main Script isnt really done yet as you can see at the saving process on the bottom of the code.

I would be super greatful if someone can help me save the data using update Async