HttpClient in MVC controller action

Question

I have a question about HttpClient. I have an ASP.NET MVC 6 project. I need call some REST api for get or post some data.

Then I have next logic. User call a server method ip/index>> server get request and call api ip/api/GetSomething>> server get response and return View for user.

Sample code:

[HttpGet]
public async Task<IActionResult> Index()
{
        try
        {
            using (var h = new HttpClient())
            {
                h.DefaultRequestHeaders.Add("Authorization", "Bearer " + token); //token i got early
                h.DefaultRequestHeaders.Add("Keep-Alive", "true");
                h.DefaultRequestHeaders.Accept.Add(new System.Net.Http.Headers.MediaTypeWithQualityHeaderValue("application/json"));

                string sQueryKadastr = _uRL + $"/api/GetSomething";

                contentSave.Headers.ContentType = new System.Net.Http.Headers.MediaTypeHeaderValue("application/json");
                var response = await h.GetAsync(sQueryKadastr);
            
                //did something with response and return View
        }
        catch (Exception ex)
        {
            g_Global.Log.Write4Web(User.GetUserName(), $"Errors: ", ex);
        }

        return View("Error");
}

My method work good (any post, get, put etc), but I know that after using dispose HttpClient, the socket continues to live. And in the future I would can get SocketException.

How can I avoid this? I cannot use one HttpClient because requests to the server can go simultaneously from different users and they will probably conflict. I mean server can get request in Index action [HttpGet] and to Index action [HttpPost] and both method will set himself header to HttpClient and URI at same the time.

Or maybe I am doing something wrong? I would be grateful for any help.

Solution for safe thread: Is setting the Authorization header in HttpClient safe?