How do I use DataStore?

I have 2 scripts that use DataStore one that gives players their cash from their last play when they join and one that saves their cash when they leave. However these scripts aren't working and I wish to know why.

PLAYER JOIN:

local Data = game:GetService("DataStoreService"):GetDataStore("ServerMoney")

game.Players.PlayerAdded:connect(function(plr)

local stats = Instance.new("IntValue",plr)
stats.Name = "leaderstats"
stats.Value = 0

local Cash = Instance.new("IntValue",stats)
Cash.Name = "Cash"
stats.Value = 0

local key = "Player-"..plr.userId

local SavedValues = Data:GetAsync(key)

if SavedValues then
    Cash.Value = SavedValues[1] 
else
    local ToSave = {Cash.Value}
    Data:SetAsync(key, ToSave)
end
end)

PLAYER LEAVE:

local Data = game:GetService("DataStoreService"):GetDataStore("ServerMoney")

game.OnClose = function()
game.Players.PlayerRemoving:connect(function(plr)
    if plr:FindFirstChild("leaderstats")then
        if plr.leaderstats:FindFirstChild("Cash")then
            local key = "Player-"..plr.userID

            local ToSave = {plr.leaderstats.Cash.Value}

            Data:SetAsync(key, ToSave)
        end
    end
end)
end