C# .Net 4.7.2 Create cert

Program.cs

using System;
using System.IO;
using System.Security.Cryptography;
using System.Security.Cryptography.X509Certificates;

namespace ConsoleApp
{
    class Program
    {
        static string Domain = "serverless.id";
        static string CommonName = Domain;
        static string Country = "ID";
        static string State = "Jawa Barat";
        static string Locality = "Bandung";
        static string Organization = "Serverless Indonesia";
        static string OrganizationalUnit = "Serverless Engineer";
        static string Email = "fajri@" + Domain;

        static int ValidYear = 5;

        static string CertOutPath = "c:\\temp\\";
        static string PrivateKeyName = Domain + "-private_key.xml";
        static string PfxKeyName = Domain + ".pfx";
        static string PemKeyName = Domain + ".pem";

        static void Main(string[] args)
        {
            GeneratePrivateKey(CertOutPath + PrivateKeyName);
            string thumbprint = GenerateKeyFromXML(PrivateKeyName);
            Console.WriteLine(thumbprint);
        }

        static void GeneratePrivateKey(string outPath)
        {
            var rsa = RSA.Create(2048);
            File.WriteAllText(outPath, rsa.ToXmlString(true));
        }

        static string GenerateKeyFromXML(string privateKeyName)
        {
            // Read from xml file
            var rsa_file = File.ReadAllText(CertOutPath + PrivateKeyName);
            var rsa = RSA.Create();
            rsa.FromXmlString(rsa_file.ToString());

            // Generate New Certificate
            var padding = RSASignaturePadding.Pkcs1;
            // 
            string subject = "CN=" + CommonName + "/C=" + Country + "/ST=" + State + "/L=" + Locality +  "/O=" + Organization + "/OU=" + OrganizationalUnit + "/emailAddress=" + Email;
            var req = new CertificateRequest(subject, rsa, HashAlgorithmName.SHA256, padding);
            var cert = req.CreateSelfSigned(DateTimeOffset.Now, DateTimeOffset.Now.AddYears(ValidYear));

            // Create PFX (PKCS #12) with private key
            File.WriteAllBytes(CertOutPath + PfxKeyName, cert.Export(X509ContentType.Pfx));

            // Create Base 64 encoded CER (public key only)
            File.WriteAllText(CertOutPath + PemKeyName,
                "-----BEGIN CERTIFICATE-----\r\n"
                + Convert.ToBase64String(cert.Export(X509ContentType.Cert), Base64FormattingOptions.InsertLineBreaks)
                + "\r\n-----END CERTIFICATE-----");

            return cert.Thumbprint;
        }
    }
}