environments/prod/public/admin/index.php
<?php
defined('YII_DEBUG') or define('YII_DEBUG', false);
defined('YII_ENV') or define('YII_ENV', 'prod');
require(__DIR__ . '/../../vendor/autoload.php');
require(__DIR__ . '/../../vendor/yiisoft/yii2/Yii.php');
require(__DIR__ . '/../../common/config/bootstrap.php');
require(__DIR__ . '/../../backend/config/bootstrap.php');
$config = yii\helpers\ArrayHelper::merge(
require(__DIR__ . '/../../common/config/main.php'),
require(__DIR__ . '/../../common/config/main-local.php'),
require(__DIR__ . '/../../backend/config/main.php'),
require(__DIR__ . '/../../backend/config/main-local.php')
);
$application = new yii\web\Application($config);
$application->run();