Hay, i cant send Tradeoffer's.   My Code is: 
SteamUser.on('webSession', function(sessionID, cookies) {
    log('Got the WebSession from the login!');
	
    SteamCommunity.setCookies(cookies); // sets the cookies for steamcommunity
    manager.setCookies(cookies); // sets the cookies for the trade-offer manager
    manager.parentalUnlock('....');
    var offer = manager.createOffer(tradeurl); // create a new offer
    offer.addTheirItem({"appid": 730, "contextid": 2, "assetid": "6658188534"}); // add a item
	
    offer.send(function(err, status) { // send a offer
        if (err) { // if it fails
            log(err + ' ' + status, true);
        } else {
            console.log("Offer #" + offer.id + " " + status);
        }
    });
}); /* TODO: A WAY TO REFRESH SESSIONS */     This gives me the following Error:   [2016:06:22-12:59:42] accountname: Error: HTTP error 403 undefined