Unable to run Async Method without Console.ReadLine() Or Console.ReadKey()

Question

I have my main method calling another method. Everything works fine as long as I use Console.Readline() or Console.ReadKey(). The minute I remove it, the project is finishing without doing completely what it is supposed to do.

private static void Main()
{
    var SQLServerName = "XXXXXXXXXXXX.database.windows.net";
    var SQLServerAdmin = "XXXXXXXXXXXX";
    var SQLServerAdminPasword = "XXXXXXXXXXXX";
    var DatabaseName = "XXXXXXXXXXXX";
    string SQLStatement = ($"TRUNCATE TABLE XXXXXXXXXXXX" + 
                           $"TRUNCATE TABLE XXXXXXXXXXXX");
    Helper.ExecuteTSQL(SQLServerName, SQLServerAdmin, SQLServerAdminPasword, DatabaseName, SQLStatement);

    List<string> Subscriptions = Helper.GetSubscriptionList();
    foreach (string Subscription in Subscriptions)
    {
        string SubscriptionID = Subscription.Replace(" ", String.Empty);
        Runner(SubscriptionID);
    }
    Console.ReadKey();
}

public static async void Runner(string SubscriptionID)
{
   var task = await RBACSnapshot.GetRBACSnapshot(SubscriptionID);   
}