NodeJS join group

var community = new SteamCommunity();
var gid = "27586976"; // Gruppen ID
var username = "loginID" // Login Name
var password = "loginPW" // Login Passwort

community.login({
  "accountName": username,
  "password": password,
  }, function(err, sessionID) {
    if(err) {
     console.log(err);
     process.exit();
     return;
    }
    community.joinGroup(gid);
});