Got "Bad request " HTTPS Post request in NodeJS

I am trying to send Https post request using NodeJS, but getting back 'Bad request'. At the same time when I send the same request via curl everything is fine. Can you help to fix the Node code:

var options = {
       host: 'api.wit.ai',
       port: 443,
       path: '/converse?v=20170611&session_id=125abc&q=Hi',
       method: 'POST',
       headers: {
           'Content-Type': 'application/json',
           'Accept': 'application/json',
           'Authorization': 'Bearer <token>'
       }
   };
var req = https.request(options, function(res) {...}

The curl query: curl -XPOST 'https://api.wit.ai/converse?v=20170611&session_id=125abc&q=Hi' \ -H "Content-Type: application/json" \ -H "Accept: application/json" \ -H 'Authorization: Bearer <token>'

via Evgeny Krivosheev