GUI open after login is successful

I am using keyauth to create a login system, my GUI is called ''Form1'', the login GUI is called ''Login'', I would like ''Form1'' to be opened after the login is successful, how I make ?

using KeyAuth;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace CxFlatDemo
{
    static class Program
    {
        /// <summary>
        /// </summary>
        [STAThread]
        static void Main()
        {
            Application.EnableVisualStyles();
            Application.SetCompatibleTextRenderingDefault(false);
            Application.Run(new Login());
        }
    }
}