Integrating twitterOauth?

If you are using composer, with default CI3 settings there will be created additional vendor directory in root location
(that's where you need to put composer.json file also). Calling new classes in your controller would be like:

PHP Code:

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

use Abraham\TwitterOAuth\TwitterOAuth;

class Welcome extends CI_Controller
{
    public function __construct()
    {
    parent::__construct();
        
        $connection = new TwitterOAuth(CONSUMER_KEY, CONSUMER_SECRET, $access_token, $access_token_secret);
        $content = $connection->get("account/verify_credentials");
    }
} 


To make this work you need to set option to true or custom path. More docs. 
 Link for composer.json file. Rest of docs for twitteroauth use.