HTTP Hanler in ASP.NET C# - How to call a http handler

string handlerUrl = String.Format(Request.Url.Scheme+"://" +Request.Url.Authority+"{0}","/Handler.ashx");

        string response = (new WebClient()).DownloadString(handlerUrl);

and we can pass parameters to processrequest function

 context.Response.ContentType = "application/x-javascript";

        MethodName = context.Request.Params["method"];

        Parameter = context.Request.Params["param"];

        CallBackMethodName = context.Request.Params["callbackmethod"];

 https://www.c-sharpcorner.com/uploadfile/37db1d/create-your-first-http-handler-in-Asp-Net-3-5/

https://www.msdotnet.co.in/2013/10/how-to-create-http-handler-application.html#.Y8zNn3ZByxU

https://www.c-sharpcorner.com/UploadFile/ca2535/call-generic-handler-using-jquery-in-Asp-Net/

https://www.c-sharpcorner.com/article/http-handlers-in-Asp-Net/