using System;

public class Program

{

    public static void Main()

    {

        var tenantId = "bea81f24-5073-4f1d-98bc-1f803bb7213c"; //replace with your tenantID

        // The GUID to be converted

        Guid guid = new Guid(tenantId);

​

        // Convert GUID to byte array

        byte[] byteArray = guid.ToByteArray();

​

        // Encode byte array to Base64 URL-safe string

        string base64Url = Convert.ToBase64String(byteArray)

                              .Replace('+', '-')

                              .Replace('/', '_')

                              .TrimEnd('=');

​

        Console.WriteLine(base64Url);

    }

}