Как принять обмен steam php?

здравствуйте у меня есть такой код

$steamIdMy ='sessionid=steam64ID';
$steamIdFr ='&partner=steam64ID';
$tradeId='&tradeofferid=tradeofferid';
$serverId='&serverid=1';
$form=$steamIdMy.$serverId.$tradeId;
$teest=' ';
$referer = 'https://steamcommunity.com/tradeoffer/tradeofferid/';
$headers = array('Cookie' =>$teest,'Timeout'=> Unirest\Request::timeout(5));
$headers['referer'] = $referer;
$response = Unirest\Request::post('https://steamcommunity.com/tradeoffer/tradeoffer/accept' ,$headers, $form);
print_r ($response);

в итоге выводит это

Unirest\Response Object
(
[code] => 403
[raw_body] => null
[body] => 
[headers] => Array
    (
        [0] => HTTP/1.1 403 Forbidden
        [Server] => Apache
        [Vary] => Accept-Encoding,Origin
        [X-Frame-Options] => SAMEORIGIN
        [Content-Security-Policy] => script-src 'self' 'unsafe-inline' 'unsafe-eval' https://steamcommunity-a.akamaihd.net/ https://api.steampowered.com/ *.google-analytics.com https://www.google.com https://www.gstatic.com https://apis.google.com; object-src 'none'; connect-src 'self' http://steamcommunity.com https://steamcommunity.com https://api.steampowered.com/ http://localhost:27060 http://store.steampowered.com/ https://store.steampowered.com/; frame-src 'self' steam: http://store.steampowered.com/ https://store.steampowered.com/ http://www.youtube.com https://www.youtube.com https://www.google.com https://sketchfab.com https://player.vimeo.com;
        [Expires] => Mon, 26 Jul 1997 05:00:00 GMT
        [Cache-Control] => no-cache
        [Content-Length] => 4
        [Content-Type] => application/json; charset=utf-8
        [Date] => Sun, 21 Jan 2018 15:56:38 GMT
        [Connection] => close
        [Set-Cookie] => Array
            (
                [0] => sessionid=ad343cb7d4538e2e532e85df; path=/
                [1] => steamCountry=RU%7C3b7b9dd1b5164f33908b3ff768aca7ba; path=/
            )
    )

)