Hi, I made this code to send offer but the problem that I got that error "Error: HTTP error 401" When I using "manager.setCookies" I got the error access denied because my limited account . So I looked for another module "node-steam-tradeoffers" and it's working with "steam-weblogon" and  "steam-web-api-key" and it's send the offers from my limited account, but I need to using your module, so I made this code which can make the api key. 
var Steam = require('steam');
var SteamWebLogOn = require('steam-weblogon');
var getSteamAPIKey = require('steam-web-api-key');
var SteamCommunity = require('steamcommunity');
var SteamTotp = require('steam-totp');
var TradeOfferManager = require('steam-tradeoffer-manager'); 
var fs = require('fs');
//var client = new SteamUser();
var community = new SteamCommunity();
var steamClient = new Steam.SteamClient();
var steamUser = new Steam.SteamUser(steamClient);
var steamFriends = new Steam.SteamFriends(steamClient);
var steamWebLogOn = new SteamWebLogOn(steamClient, steamUser);
var manager = new TradeOfferManager({
  "steam": steamClient, // Polling every 30 seconds is fine since we get notifications from Steam
  "domain": "localhost", // Our domain is example.com
  "language": "en" // We want English item descriptions
});
if (fs.existsSync('polldata.json')) {
  manager.pollData = JSON.parse(fs.readFileSync('polldata.json'));
}
steamClient.connect();
steamClient.on('connected', function() {
  steamUser.logOn({
    account_name: '*********',
    password: '***********',
    two_factor_code: SteamTotp.generateAuthCode('**********************')
  });
});
steamClient.on('logOnResponse', function(logonResp) {
  if (logonResp.eresult == Steam.EResult.OK) {
    console.log('Logged in!');
    steamWebLogOn.webLogOn(function(sessionID, newCookie) {
      getSteamAPIKey({
        sessionID: sessionID,
        webCookie: newCookie
      }, function(err, APIKey) {
       manager.apiKey = APIKey;
        var offer = manager.createOffer("************");
    offer.addMyItem({"appid": 730, "contextid": 2, "assetid": "655530455"});
    offer.send(function(err, status) {
        if (err) {
            console.log("send" + err);
        } else {
            console.log("Offer #" + offer.id + " " + status);
        }
    });
      });
      community.setCookies(newCookie);
    community.startConfirmationChecker(10000, '*********************************');
    });
  }
 });