RestSharp Post Method to Upload Video File to PHP API

[sandeep singh]

I am new to RestSharp, using C# WPF, i want to upload a video (mp4) file to server using PHP API and RestSharp.

var Client = new RestClient("https://www.XXXX.com/");
                var Request = new RestRequest("FILE.php", Method.POST);
                Request.AddParameter("uniqueID", DeviceID);
               Request.AddParameter("POSTID", POSTID);
               Request.AddParameter("outPutVideoPath", outPutVideoPath);
               Request.AddParameter("accesstoken", "TOKEN");

This is not uploading file.

Please advice.

Thanks