I have a project based from Yii Framework. I followed this guide to implement boostrap for my yii project but I'm getting error:

```
Invalid Bootstrap path and CDN URL not set. Set vendor.twbs.bootstrap.dist alias or cdnUrl parameter in the configuration file. 

```

Here's the URL <http://www.getyiistrap.com/site/started>

I followed everything. I didn't use composer. I just downloaded the zip file.

Here's my config file for reference:

```
<?php

```

// uncomment the following to define a path alias
// Yii::setPathOfAlias('local','path/to/local-folder');

// This is the main Web application configuration. Any writable
// CWebApplication properties can be configured here.
return array(
 'basePath'=>dirname(**FILE**).DIRECTORY\_SEPARATOR.'..',
 'name'=>'My Web Application',

```
// preloading 'log' component
'preload'=>array('log'),

 // path aliases
'aliases' => array(
    'bootstrap' => realpath(__DIR__ . '/../extensions/bootstrap'), // change this if necessary
),

// autoloading model and component classes
'import'=>array(
    'application.models.*',
    'application.components.*',
            'bootstrap.helpers.*',

),

'modules'=>array(
    // uncomment the following to enable the Gii tool

    'gii'=>array(
        'class'=>'system.gii.GiiModule',
        'password'=>'password',
        // If removed, Gii defaults to localhost only. Edit carefully to taste.
        'ipFilters'=>array('127.0.0.1','::1'),
                    'generatorPaths' => array('bootstrap.gii'),
    ),

),

// application components
'components'=>array(

    'user'=>array(
        // enable cookie-based authentication
        'allowAutoLogin'=>true,
    ),

        'bootstrap' => array(
            'class' => 'bootstrap.components.TbApi',   
        ),

    // uncomment the following to enable URLs in path-format

    'urlManager'=>array(
        'urlFormat'=>'path',
        'rules'=>array(
            '<controller:\w+>/<id:\d+>'=>'<controller>/view',
            '<controller:\w+>/<action:\w+>/<id:\d+>'=>'<controller>/<action>',
            '<controller:\w+>/<action:\w+>'=>'<controller>/<action>',
        ),
    ),

    // database settings are configured in database.php
    'db'=>require(dirname(__FILE__).'/database.php'),

    'errorHandler'=>array(
        // use 'site/error' action to display errors
        'errorAction'=>'site/error',
    ),

    'log'=>array(
        'class'=>'CLogRouter',
        'routes'=>array(
            array(
                'class'=>'CFileLogRoute',
                'levels'=>'error, warning',
            ),
            // uncomment the following to show log messages on web pages
            /*
            array(
                'class'=>'CWebLogRoute',
            ),
            */
        ),
    ),

),

// application-level parameters that can be accessed
// using Yii::app()->params['paramName']
'params'=>array(
    // this is used in contact page
    'adminEmail'=>'webmaster@example.com',
),
);

```

I followed where to put the bootstrap files. I've been searching on the internet but can't find an answer. Thanks