My datastore loop script won't let me save all the data, it just isn't working, any help?

I have a datastore script for a shop, insteaad of having to manually name and give value to all items, I wanna make a loop that saves it and retrieves it, apparently, it hasn't been working so far, any help??

local storage = game:GetService("DataStoreService"):GetDataStore("I_AM_ON_YOUTUBE")
game.Players.PlayerAdded:Connect(function(plr)
	print("Loading")
	local folder = Instance.new("Folder")
	folder.Parent = plr
	folder.Name = "Shop_Stats"
	local a = 0
	local rrr = {}
	local key = plr.UserId
	for _, v in pairs(plr.PlayerGui:WaitForChild("Shop_GUI"):WaitForChild("Shop"):WaitForChild("Upgrades"):GetChildren()) do
		print("Entering shop")
		if v.ClassName == "TextButton" then
			a = a + 1
			local n = Instance.new("IntValue")
			n.Parent = folder
			n.Name = v.Name
			if storage:GetAsync(key) then
			n.Value = storage:GetAsync(key)[a]
			print("Got async data")
			else
				for _, v in pairs(plr.Shop_Stats:GetChildren()) do
					table.insert(rrr, v.Value)
				end
				storage:SetAsync(key, rrr)
			end
		end
	end
end)
game.Players.PlayerRemoving:Connect(function(plr)
	print("Saving")
	local key = plr.UserId
	local valuesToSave = {}
	local shop = plr.Shop_Stats
	for _, v in pairs(shop:GetChildren()) do
		table.insert(valuesToSave, tostring(v.Value))
	end
	storage:SetAsync(key, valuesToSave)
	print("Saved")
end)

it won't print("Saved")

Everything else it will do, I may be having a bad format in saving and loading, if so, please correct me.