How to create environment variables with the the package vlucas/phpdotenv for yii2 advance template

I installed the package:

composer require vlucas/phpdotenv

and in the root of my project i have a .env file with some configuration variable.

Now i try to use PHP dotenv to get the ENV variable availables to the prod and dev environments.
So, to do this, i’ve modified the yii file inside of environments/dev and environments/prod folders in order to get env variables available inside the project.
So the yii file is :

#!/usr/bin/env php
<?php
/**
 * Yii console bootstrap file.
 */
defined('YII_DEBUG') or define('YII_DEBUG', true);
defined('YII_ENV') or define('YII_ENV', 'dev');

require __DIR__ . '/vendor/autoload.php';
require __DIR__ . '/vendor/yiisoft/yii2/Yii.php';
require __DIR__ . '/common/config/bootstrap.php';
require __DIR__ . '/console/config/bootstrap.php';

$dotenv = DotenvDotenv::createImmutable(__DIR__ . '/');
$dotenv->load();

$config = yiihelpersArrayHelper::merge(
    require __DIR__ . '/common/config/main.php',
    require __DIR__ . '/common/config/main-local.php',
    require __DIR__ . '/console/config/main.php',
    require __DIR__ . '/console/config/main-local.php'
);

$application = new yiiconsoleApplication($config);
$exitCode = $application->run();
exit($exitCode);

For example i modified my main-local.php inside environmentscommon folder

'db' => [
            'class' => yiidbConnection::class,
            'dsn' => 'mysql:host=localhost;dbname='.$_ENV['DB_NAME'],
            'username' => $_ENV['DB_USER'],
            'password' => $_ENV['DB_PASSWORD'],
            'charset' => 'utf8',
            'enableSchemaCache' => $_ENV['DB_USE_CACHE'],
            'schemaCacheDuration' => 3600,
            'schemaCache' => 'cache',
        ],

But when i run php init $_ENV variable is empty. Is this the correct way to set .env file? what am I doing wrong?

This is my .env file

# APPLICATION CONFIG
APP_NAME="Yii -CMS"
APP_LANGUAGE=it
APP_CHARSET=utf-8
APP_ENV=dev # [dev | test | prod]
APP_DEBUG=true # use 'false' in production

# DATABASE CONFIG
DB_HOST=localhost
DB_CONNECTION=mysql
DB_PORT=3306
DB_USER=root
DB_PASSWORD=''
DB_NAME=yiicms
DB_USE_CACHE=false # use 'true' in production