Yii2 Backend show 500 internal server error - yii2

Question

When I access http://alpha.myweb.com/administrator/company I got 500 Internal Server Error
But I can access it localhost.
How I can debug my problem?
Here is my backend\config\main.php
<?php
$params = array_merge(
require(__DIR__ . '/../../common/config/params.php'),
require(__DIR__ . '/../../common/config/params-local.php'),
require(__DIR__ . '/params.php'),
require(__DIR__ . '/params-local.php')
);
return [
'id' => 'app-backend',
'basePath' => dirname(__DIR__),
'controllerNamespace' => 'backend\controllers',
'bootstrap' => ['log'],
'modules' => [
'agent' => [
'class' => 'backend\modules\agent\Agent',
],
'company' => [
'class' => 'backend\modules\company\Company',
'defaultRoute' => 'home',
],
'vendor' => [
'class' => 'backend\modules\vendor\Vendor',
'defaultRoute' => 'default',
],
'services' => [
'class' => 'backend\modules\services\Services',
'defaultRoute' => 'site',
],
],
'homeUrl' => 'http://alpha.myweb.com/administrator',
'components' => [
'formatter' => [
'class' => 'yii\i18n\Formatter',
'thousandSeparator' => '.',
'decimalSeparator' => ',',
//'currencyCode' => '$'
],
'user' => [
'identityClass' => 'common\models\UserBeo',
'enableAutoLogin' => false,
//'authTimeout' => 120
],
'log' => [
'traceLevel' => YII_DEBUG ? 3 : 0,
'targets' => [
[
'class' => 'yii\log\FileTarget',
'levels' => ['error', 'warning'],
],
],
],
'errorHandler' => [
'errorAction' => 'site/error',
],
'urlManager' => [
'class' => 'yii\web\UrlManager',
'enablePrettyUrl' => true,
'showScriptName' => false,
'showScriptName' => false,
/*
'rules' => array(
'<controller:\w+>/<id:\d+>' => '<controller>/view',
'<controller:\w+>/<action:\w+>/<id:\d+>' => '<controller>/<action>',
'<controller:\w+>/<action:\w+>' => '<controller>/<action>',
),
*/
],
'request' => [
'baseUrl' => '/administrator',
'parsers' => [
'application/json' => 'yii\web\JsonParser',
]
],
/*
'response' => [
'format' => yii\web\Response::FORMAT_JSON,
'charset' => 'UTF-8',
// ...
]
*/
],
'params' => $params,
];
Here is my .htaccess
# prevent directory listings
Options -Indexes
IndexIgnore */*
# follow symbolic links
Options FollowSymlinks
RewriteEngine on
RewriteRule ^administrator(/.+)?$ backend/web/$1 [L,PT]
RewriteRule ^(.+)?$ frontend/web/$1
#RewriteCond %{HTTP_HOST} ^alpha\.myweb\.com [NC]
#RewriteRule ^(.*)$ http://alpha.myweb.com/$1 [L,R=301]
So What cause this problem, because I can open frontend website without error.
Please let me know if you need more information.
Thanks in advance, any help appreciated.