Callback is not a function when sending a trade offer

[Neyot]

Hello there. I seem to be having a problem when attempting to send a Trade Offer. The items seem to be added to the trade okay, but when it comes to actually sending the trade, I get the error:

\node_modules\steam-tradeoffer-manager\lib\classes\TradeOffer.js:526
                    callback(null, 'pending');
                    ^

TypeError: callback is not a function
    at SteamCommunity.<anonymous> (C:\Users\Alex\Desktop\SteamBot Files\NODE JSBTC KEY BOT\node_modules\steam-tradeoffer-manager\lib\classes\TradeOffer.js:526:4)
    at Request._callback (\node_modules\steamcommunity\components\http.js:62:14)
    at Request.self.callback (\node_modules\steamcommunity\node_modules\request\request.js:200:22)
    at emitTwo (events.js:87:13)
    at Request.emit (events.js:172:7)
    at Request.<anonymous> (\node_modules\steamcommunity\node_modules\request\request.js:1067:10)
    at emitOne (events.js:82:20)
    at Request.emit (events.js:169:7)
    at IncomingMessage.<anonymous> (\node_modules\steamcommunity\node_modules\request\request.js:988:12)

    at emitNone (events.js:72:20)

My code for sending the trade offer is:

function sendCrates(steamID, amount) {
  if (!amount) {
    return true;
  }
  offers.loadInventory(appid.CSGO, contextid.CSGO, true, function (err, inventory) {
    if (err) {
      logger.error(err);
    } else {
      var pool = inventory.filter(function (item) {
        return item.tags.some(function(element, index, array) {
          return element.internal_name == "CSGO_Tool_WeaponCase_KeyTag";
        });
      });

      if (pool.length === 0) {
        client.chatMessage(steamID, "We don't have any keys available. Sorry!");
        return true;
      } else if (amount > pool.length) {
        logger.debug('User requested ' + amount + ' of keys. I only have ' + pool.length + ' available.');
        client.chatMessage(steamID, 'I only have ' + pool.length + ' keys available. Sorry about that.');
        amount = pool.length;
      }
      var finalAddTradeItems = [];
      var trade = offers.createOffer(steamID);

      logger.debug('Adding ' + amount + ' keys to trade offer for ' + steamID);

      for (var i = 0; i <= amount-1; i++) {
        finalAddTradeItems[i] = pool[i];
          if(i == (amount-1)) {
            trade.addMyItems(finalAddTradeItems);
            break;
          };
        };

      trade.send('Here are the keys you asked for!', function (err, status) {
        if (err) {
          logger.error(err);
          client.chatMessage(steamID, 'Something went wrong when trying to send the trade offer. Steam message: ' + err);
        } else if (status == 'pending') {
          logger.info('Trade offer sent to ' + steamID + ' for ' + amount + ' keys.');
          client.chatMessage(steamID, 'Trade offer sent. Awaiting mobile confirmation.');
          SteamMobileConfirms(true, false, false, steamID, trade.id);
        };
      });
    };
  });
};

I couldn't find anything related to this in the past issues and everything on the internet is stating that I haven't got a callback, although I have. I understand that my code is quite messy. I'm still relatively new to this.

Thank you in advance.

Edit: The trade is actually sending, as it goes to my Steam confirmation page.

[Neyot]

It was because I still included a message in the trade.send function.