private static async Task TemplateWithHelper()
{
String apiKey = Environment.GetEnvironmentVariable("SENDGRID_APIKEY", EnvironmentVariableTarget.User);
dynamic sg = new SendGrid.SendGridAPIClient(apiKey, "https://api.sendgrid.com");
Email from = new Email("[email protected]");
String subject = "I'm replacing the subject tag";
Email to = new Email("[email protected]");
Content content = new Content("text/html", "I'm replacing the <strong>body tag</strong>");
Mail mail = new Mail(from, subject, to, content);
mail.TemplateId = "13b8f94f-bcae-4ec6-b752-70d6cb59f932";
mail.Personalization[0].AddSubstitution("-name-", "Example User");
mail.Personalization[0].AddSubstitution("-city-", "Denver");
dynamic response = await sg.client.mail.send.post(requestBody: mail.Get());
Console.WriteLine(response.StatusCode);
Console.WriteLine(response.Body.ReadAsStringAsync().Result);
Console.WriteLine(response.Headers.ToString());
Console.ReadLine();
}