public/admin/index.php
<?php
require(__DIR__ . '/../../app/vendor/autoload.php');
require(__DIR__ . '/../../app/base/config/env.php');
require(__DIR__ . '/../../app/vendor/yiisoft/yii2/Yii.php');
require(__DIR__ . '/../../app/base/config/bootstrap.php');
require(__DIR__ . '/../../app/back/config/bootstrap.php');
$config = yii\helpers\ArrayHelper::merge(
require(__DIR__ . '/../../app/base/config/main.php'),
require(__DIR__ . '/../../app/back/config/main.php')
);
$application = new yii\web\Application($config);
$application->run();