Setting Authorization Headers and accessing data response in Sabre in ASP.NET MVC C#

I am building a website to search for flights data using Insta Flight Search API by Sabre. After thoroughly reading the docs provided by them and testing the API in the API Explorer where everything worked perfectly giving me the exact idea how the API will work.

To start with i just created a simple form with 2 select boxes which are providing the source and destination IATA codes, and 2 date input boxes giving the departure and return date. I have been searching for solutions for more than a week and tried various solutions i found, but every time i get either a 400 BAD REQUEST or 401 UNAUTHORIZED response.

I also checked the Demo Gallery but at the time of writing there was no sample for C#, even on Stack-Overflow there are only 78 questions tagged sabre and just 1 tagged sabre and C#

I contacted the support but received a response.

Please bear in mind that we do not provide code support. Could you please share the XML (Sabre) files?

I know i am missing something really silly, but after trying everything i can think of, i am resorting to the community for help. I am attaching both the code files.

Note: Commented code represents the various methods i have tried

Controller Code :

using System;
using System.Net;
using System.Net.Http;
using System.Web.Mvc;
using System.Threading.Tasks;

namespace Sabre_sample_1.Controllers
{
    public class HomeController : Controller
    {
        public async Task<ActionResult> Index()
        {
            if (Request.HttpMethod == "POST")
            {
            string Origin = Request.Form["Origin"];
            string Destination = Request.Form["Destination"];
            DateTime Departure = Convert.ToDateTime(Request.Form["Departure"]);
            string departuredatestr = Departure.Year.ToString() + "-" + Departure.Month.ToString() + "-" + Departure.Day.ToString();
            DateTime Return = Convert.ToDateTime(Request.Form["Return"]);
            string returndatestr = Return.Year.ToString() + "-" + Return.Month.ToString() + "-" + Return.Day.ToString();

            WebClient datawebclient = new WebClient();
            string url = "https://" + "api.test.sabre.com/v1/shop/flights?origin=" + Origin + "&destination=" + Destination
                + "&departuredate=" + departuredatestr + "&returndate=" + returndatestr + "&onlineitinerariesonly=N"
                + "&limit=10&offset=1&eticketsonly=N&sortby=totalfare&order=asc&sortby2=departuretime&order2=asc"
                + "&pointofsalecountry=US";
            string data = string.Empty;
            string AccessToken = "*Access Token*";
            //datawebclient.Headers.Add("Authorization", "Bearer " + AccessToken);
            //datawebclient.Headers.Add(HttpRequestHeader.Authorization, "Bearer " + AccessToken);
            //datawebclient.Headers.Add(HttpRequestHeader.Authorization, AccessToken);
            //data = datawebclient.DownloadString(url);

            //HttpClient httpClient = new HttpClient();
            //httpClient.DefaultRequestHeaders.Authorization = new System.Net.Http.Headers.AuthenticationHeaderValue("Bearer", AccessToken);
            //data = await httpClient.GetStringAsync(url);

            using (var client = new HttpClient())
            {
                //url = "https://www.theidentityhub.com/{tenant}/api/identity/v1";
                client.DefaultRequestHeaders.Add("Authorization", "Bearer " + AccessToken);
                data = await client.GetStringAsync(url);
                // Parse JSON response.

            }

            ViewBag.url = url;
            ViewBag.data = data;
            //RedirectResult redirectresult = new RedirectResult(url);
        }
        return View();
    }
}
}

Index.cshtml :

<form class="form-horizontal" method="post">
<fieldset>
    <legend>Enter Details</legend>
    <div class="form-group">
        <label for="select" class="col-lg-2 control-label">Origin</label>
        <div class="col-lg-10">
            <select class="form-control" name="Origin" required>
                <option></option>
                <option value="JFK">John F. Kennedy International Airport</option>
                <option value="EZE">Ministro Pistarini</option>
                <option value="MIA">Miami International Airport</option>
            </select>
        </div>
    </div>
    <div class="form-group">
        <label for="select" class="col-lg-2 control-label">Destination</label>
        <div class="col-lg-10">
            <select class="form-control" name="Destination" required>
                <option></option>
                <option value="JFK">John F. Kennedy International Airport</option>
                <option value="EZE">Ministro Pistarini</option>
                <option value="MIA">Miami International Airport</option>
            </select>
        </div>
    </div>
    <div class="form-group">
        <label for="inputEmail" class="col-lg-2 control-label">Departure</label>
        <div class="col-lg-10">
            <input type="date" class="form-control" name="Departure"required>
        </div>
    </div>
    <div class="form-group">
        <label for="inputEmail" class="col-lg-2 control-label">Return</label>
        <div class="col-lg-10">
            <input type="date" class="form-control" name="Return" required>
        </div>
    </div>
    <div class="form-group">
        <div class="col-lg-10 col-lg-offset-2">
            <input name="endpointName" type="hidden" value="Air Search" class="form-control">
            <input name="methodName" type="hidden" value="InstaFlights Search" class="form-control">
            <input name="httpMethod" type="hidden" value="GET" class="form-control">
            <input name="methodUri" type="hidden" value="/v1/shop/flights" class="form-control">
            <button type="reset" class="btn btn-default">Cancel</button>
            <button type="submit" class="btn btn-primary">Submit</button>
        </div>
    </div>
</fieldset>
</form>
<h2>Url</h2>
@ViewBag.url
<hr />
<h2>Data</h2>
@ViewBag.data

Other Stack Overflow Questions which are closest to my problem, but didn't solved my problem.

FINAL EDIT

After weeks of struggling with the possible solution, i found the answer in the formatting of the response. A JSON object contains the objects as strings in " enclosing, but the whole response is also a string which makes the internal " enclosing to \"

But last month have made me realize the need for a proper tutorial for Sabre for developers in ASP.NET MVC C#, so i will publishing a blog post and a Nuget Package for other peers. I'll share the links once they are live.

Solution

Happy Coding.