What is issue in my code Sandbox paypal future payment

I have alredy enable future payments permission in my app and using developer dashboard.but not working yet please find error http://developer.paypal.com/ and log in https://developer.paypal.com/developer/accountStatus there you can see what permits you have.

 $data = array(
                "intent" => "authorize",
                "payer" => array(
                    "payment_method" => "paypal"
                ),
                "transactions" => array(
                    array("amount" => array(
                        "currency" => "USD",
                        "total" => "1.88"
                    ),
                        "description" => "future of sauces")
                ));

        $data_string = json_encode($data);
        $ch = curl_init();
        curl_setopt($ch, CURLOPT_URL, "https://api.sandbox.paypal.com/v1/payments/payment");
        $headers = array(
            'Content-Type: application/json',
            'PayPal-Client-Metadata-Id: d6743cbb53ea4470a53bfe458f0cb885',
            'Authorization: Bearer A103.B7d5318JDS6NA1zGh02avjCx16oxnBPadUat5z9SlGVGEiOhoAeMuqyz0anGSICS.FAkzECypTS1IXfemHcpVa5yyrGu',
        );
        curl_setopt($ch, CURLOPT_HTTPHEADER, $headers);
        //curl_setopt($ch, CURLINFO_HEADER_OUT, true);
        curl_setopt($ch, CURLOPT_POST, true);
        curl_setopt($ch, CURLOPT_POSTFIELDS, $data_string);
        $result = curl_exec($ch);
        $information = curl_getinfo($ch);
        curl_close($ch);
        print_r($information);
        die;

Out put here

{"name":"PERMISSION_DENIED","message":"No permission for the requested operation","information_link":"https://developer.paypal.com/docs/api/#PERMISSION_DENIED","debug_id":"5b39efd4cf370"}Array
(
    [url] => https://api.sandbox.paypal.com/v1/payments/payment
    [content_type] => application/json
    [http_code] => 403
    [header_size] => 592