DataStore not Saving Data?

Hello

I wanted to make a DataStore script for my game (Script in ServerScriptService) and I tried using that and it doesn't work, can someone explain me why? The script including 49 lines.

Here is the script:

ocal DataStoreService = game:GetService("DataStoreService")

local myDataStore = DataStoreService:GetDataStore("myDataStore")

game.Players.PlayerAdded:Connect(function(player)
    local leaderstats = Instance.new("Folder")
    leaderstats.Name = "leaderstats"
    leaderstats.Parent = player

    local Coins = Instance.new("IntValue")
    Coins.Name = "Coins"
    Coins.Parent = leaderstats

    local playerUserId = "Player_"..player.UserId


    local data
    local success, errormessage = pcall(function()
         data = myDataStore:GetAsync(playerUserId)
    end)



    if success then
        Coins.Value = data
    end



end)


game.Players.PlayerRemoving:Connect(function(player)
    local playerUserId = "Player_"..player.UserId

    local data = player.leaderstats.Coins.Value

    local success, errormessage = pcall(function()
        myDataStore:SetAsync(playerUserId, data)
    end)

    if success then
        print("Data successfully saved!")
    else
        print("There was an error!")
        warn(errormessage)
    end

end)