dans mon Controller API appelé Payment, j'ai la méthode suivante:

[HttpPost]
public HttpResponseMessage Charge(Payment payment)
{
    var processedPayment = _paymentProcessor.Charge(payment);
    var response = Request.CreateResponse(processedPayment.Status != "PAID" ? HttpStatusCode.ExpectationFailed : HttpStatusCode.OK, processedPayment);
    return response;
}

dans ma page HTML j'ai:

$.ajax({
        type: "POST",
        contentType: "application/json; charset=utf-8",
        url: "http://localhost:65396/api/payment/charge",
        data: $('#addPayment').serialize(),
        dataType: "json",
        success: function (data) {
            alert(data);
        }
    });

Chaque fois que je lance le POST, j'obtiens

"NetworkError: 405 Method Not Allowed - http://localhost:65396/api/payment/charge"

Ce qui me manque?

je vous Remercie.

UPDATE

Voici les informations de routage (par défaut)

 routes.MapHttpRoute(
                name: "DefaultApi",
                routeTemplate: "api/{controller}/{id}",
                defaults: new { id = RouteParameter.Optional }
            );

            routes.MapRoute(
                name: "Default",
                url: "{controller}/{action}/{id}",
                defaults: new { controller = "Home", action = "Index", id = UrlParameter.Optional }
            );