using System;
using System.Net.Http;
using System.IO;
using System.Threading.Tasks;
public class Program
{
static void Main(string[] args)
{
Task.Run(async () =>
{
string base64img = "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";
string urlpost = "https://httpbin.org/anything";
var bytes = Convert.FromBase64String(base64img);
var contents = new System.Net.Http.StreamContent(new MemoryStream(bytes));
var client = new HttpClient();
var response = await client.PostAsync(urlpost,contents);
Console.WriteLine(response);
}).GetAwaiter().GetResult();
}
}