Note- Use https:// in the url.
using System;
using System.Net;
using System.IO;
public class Program
{
public static void Main()
{
string remoteUrl = string.Format("https://unfurl.io/api/v2/preview?api_token=yourapitoken&url=https://www.google.com");
HttpWebRequest httpRequest = (HttpWebRequest)WebRequest.Create(remoteUrl);
WebResponse response = httpRequest.GetResponse();
StreamReader reader = new StreamReader(response.GetResponseStream());
string result = reader.ReadToEnd();
Console.WriteLine(result);
}
}