检查是否创建了以下自定义文件并进行正确的配置

1. config/backpack/base.php
2. config/backpack/crud.php
3. config/backpack/permissionmanager.php

如果任何一个文件不存在或没有正确配置，可能会导致无法访问管理面板。在这种情况下，请确保这些文件正确创建并配置。以下是示例配置文件及其内容。

config/backpack/base.php

 env('APP_NAME', 'Laravel'),

    /*
    |--------------------------------------------------------------------------
    | Application Environment
    |--------------------------------------------------------------------------
    |
    | This value determines the "environment" your application is currently
    | running in. This may determine how you prefer to configure various
    | services your application utilizes. To learn more see
    | https://laravel.com/docs/configuration
    |
    */

    'env' => env('APP_ENV', 'production'),

    /*
    |--------------------------------------------------------------------------
    | Application Debug Mode
    |--------------------------------------------------------------------------
    |
    | When your application is in debug mode, detailed error messages with
    | stack traces will be shown on every error that occurs within your
    | application. If disabled, a simple generic error page is shown.
    |
    */

    'debug' => env('APP_DEBUG', false),

    /*
    |--------------------------------------------------------------------------
    | Application URL
    |--------------------------------------------------------------------------
    |
    | This URL is used by the console to properly generate URLs when using
    | the Artisan command line tool. You should set this to the root of
    | your application so that it is used when running Artisan tasks.
    |
    */

    'url' => env('APP_URL', 'http://localhost'),

    /*
    |--------------------------------------------------------------------------
    | Application Timezone
    |--------------------------------------------------------------------------
    |
    | Here you may specify the default timezone for your application, which
    | will be used by the PHP date and date-time functions. We have gone
    |