DataStore not working?

I'm trying to use DataStore, I have two scripts, a saving and a loading script, inside ServerScriptService. I'm trying to save points, put there by an edited LinkedLeaderboard script, when the game closes, then the other script is just supposed to load them when they come back. Here's the saving script:

game.OnClose = function()
	for i,v in pairs(game.Players:GetPlayers()) do
		local ds = game:GetService("DataStoreService"):GetDataStore("savepoints")
		local key = "user_"..v.userId
		ds:UpdateAsync(key, function(oldValue)
			local newValue = oldValue or 0
			newValue = v.leaderstats.Points
			return newValue
		end)
	end
	wait(5)
	
end

And the loading script:

game.Players.PlayerAdded:connect(function(p)
	local ds = game:GetService("DataStoreService"):GetDataStore("savepoints")
	local loadpoints = ds:GetAsync("user_"..p.userId)
	p.leaderstats.Points = loadpoints
end)

I'm getting the error leaderstats isn't a valid member of player, when it should be since it's put there by the linked leaderboard. I don't know if this is the only error, could you help me out? I just learned how to use datastore today, so I don't think I got it all right.

Thanks!

I know this might not help with your answer but I do have a script in my models called "datastore leaderboard", it adds 50 points everytime a player joins. Try it out :), should help out with your understanding. Also try using the :OnUpdate() method.