Routine execution in the background via Hangfire (ASP.NET Webforms)

Question

I am in need of doing a background run on my system. For this I found the Hangfire tool. I made the settings according to the documentation and am getting the error: Value cannot be null. Parameter name: method

Below my code:

public class Global : HttpApplication
{
    private string connectionString = System.Configuration.ConfigurationManager.ConnectionStrings["connectionString"].ConnectionString;
    private BackgroundJobServer _backgroundJobServer;

    void Application_Start(object sender, EventArgs e)
    {
        // Code that runs on application startup
        RouteConfig.RegisterRoutes(RouteTable.Routes);
        BundleConfig.RegisterBundles(BundleTable.Bundles);

        var storage = new SqlServerStorage(connectionString); // db_HangFire is the connection string for Sql Server DB used as Job Storage for HangFire for processing 
        var options = new BackgroundJobServerOptions();
        _backgroundJobServer = new BackgroundJobServer(options, storage);
        _backgroundJobServer.Start(); // start BackgroundJobServer process
        JobStorage.Current = storage; // assign the storage to Current

    }

    protected void Application_End(object sender, EventArgs e)
    {
        _backgroundJobServer.Dispose(); // Dispose the BackgroundJobServer Object
    }
}


namespace HangFireWebForms
{
    public partial class _Default : Page
    {
        protected void Page_Load(object sender, EventArgs e)
        {

        }

        protected void btnEnqueue_Click(object sender, EventArgs e)
        {

            BackgroundJob.Enqueue(() => HangFireTask(this.txtMensagem.Text));
        }

        private void HangFireTask(string message)
        {
            this.lblHangFireResultTask.Text = message;
        }
    }
}