"TypeError: Alexa.handler is not a function"

'use strict';  
const Alexa = require('ask-sdk'); 

const APP_ID = 'insert my ID here'; 

const handlers = {  
  'LaunchRequest': function () { 
  this.emit(':tell', 'welcome to dog pictures');  
  },  
  'AMAZON.HelpIntent': function () {
  this.emit(':tell', 'you can ask for a dog picture by saying dog number 1');  
  },
  'AMAZON.CancelIntent': function () {  
  this.emit(':tell', 'bye bye, have a nice day'); 
  },  
  'AMAZON.StopIntent': function () { 
  this.emit(':tell', 'bye bye, have a nice day');  
  } 
}; 

exports.handler = function (event, context) { 
  const alexa = Alexa.handler(event, context);  
  alexa.APP_ID = APP_ID;  
  alexa.registerHandlers(handlers);  
  alexa.execute();  
}; 

console.log;

Using the alexa-skills-kit-sdk-for-nodejs and this as an index.js i keep getting the error: "TypeError: Alexa.handler is not a function"

I am trying to connect an alexa Skill with AWS Lambda Function.

I can't figure this out on my own. Any help would be appreciated. Thanks for reading this :)