test.cs

[HttpPost]
public bool WebHook([FromBody] object request) {

	dynamic ProcessingRequest = JObject.Parse(request.ToString());

	HttpClient client = new HttpClient();
	HttpResponseMessage responseMessage = client.GetAsync(ProcessingRequest.RetrieveDocumentUrl.Value).Result;

	if (responseMessage.IsSuccessStatusCode) { 
		string data = responseMessage.Content.ReadAsStringAsync().Result;
		System.IO.File.WriteAllBytes("App_Data/" + ProcessingRequest.Id.Value + ".pdf", Convert.FromBase64String(data));
		return true;
	}
	else
		return true;
}