Why, Access-Control-Allow-Origin does not work, in Codeigniter Rest-Server

I want to get data from one of BLOCKCHAIN ​​API....

But I get a small problem, where I want to access the API and inadvertently API BLOCKCHAIN ​​using 'CORS HEADER' method, after I use 'AJAX GET REQUEST' anddddddd taraaaaaaa I get Error :).

in Controller Cart.php

<?php
defined('BASEPATH') OR exit('No direct script access allowed');

class Cart extends CI_Controller {

    /**
     * Index Page for this controller.
     *
     * Maps to the following URL
     *      http://example.com/index.php/welcome
     *  - or -
     *      http://example.com/index.php/welcome/index
     *  - or -
     * Since this controller is set as the default controller in
     * config/routes.php, it's displayed at http://example.com/
     *
     * So any other public methods not prefixed with an underscore will
     * map to /index.php/welcome/<method_name>
     * @see https://codeigniter.com/user_guide/general/urls.html
     */
    public function __construct()
    {
        parent::__construct();
        header("Access-Control-Allow-Methods: GET, OPTIONS");
        header("Access-Control-Allow-Headers: Content-Type, Content-Length, Accept-Encoding");
        if ( "OPTIONS" === $_SERVER['REQUEST_METHOD'] ) {
        die();
        }
    }
    public function index()
    {
        $this->load->view('cart_view');
    }
}

in Asyc.js

$.getJSON( "https://blockchain.info/rawaddr/1N1WJYDUgaBrk9eUfawSYurs9ZtKcVVfTE", function( data ) {
  console.log(data);
});

i got error

XMLHttpRequest cannot load https://blockchain.info/rawaddr/1N1WJYDUgaBrk9eUfawSYurs9ZtKcVVfTE. No 'Access-Control-Allow-Origin' header is present on the requested resource. Origin 'http://localhost' is therefore not allowed access.