付款流程后，Paypal重定向页面

I want to display a template page after the payment process with paypal. This is the code of the paypal button referring to the redirect page:

<input type="hidden" name="return" value="http://site.mysite.local:83/buyOk">


<input type="hidden" name="rm" value="2"> //return URL using POST method

I've created a template php file called buy_process_ok.html.php and in the controller the function:

    /**
     * @Route("/buyOk")
     */

    public function buyProcessOkAction() {

        return $this->renderView('UserBundle:Account:buy_process_ok.html.php');

    }

At the end of the payment process i get this error:

No route found for "POST /buyOk"

Where I'm wrong?