getting error in setting up Milon barcode package laravel 8

php artisan make:controller ProductController

Fatal error: Uncaught ReflectionException: Class env does not exist in C:\wamp64\www\laravel-demo\vendor\laravel\framework\src\Illuminate\Container\Container.php:877 Stack trace: #0 C:\wamp64\www\laravel-demo\vendor\laravel\framework\src\Illuminate\Container\Container.php(877): ReflectionClass->__construct('env') #1 C:\wamp64\www\laravel-demo\vendor\laravel\framework\src\Illuminate\Container\Container.php(758): Illuminate\Container\Container->build('env') #2 C:\wamp64\www\laravel-demo\vendor\laravel\framework\src\Illuminate\Foundation\Application.php(841): Illuminate\Container\Container->resolve('env', Array, true) #3 C:\wamp64\www\laravel-demo\vendor\laravel\framework\src\Illuminate\Container\Container.php(694): Illuminate\Foundation\Application->resolve('env', Array) #4 C:\wamp64\www\laravel-demo\vendor\laravel\framework\src\Illuminate\Foundation\Application.php(826): Illuminate\Container\Container->make('env', Array) #5 C:\wamp64\www\laravel-demo\vendor\laravel\framework\src\Illuminate\Container\Container.php(1423): Il in C:\wamp64\www\laravel-demo\vendor\laravel\framework\src\Illuminate\Container\Container.php on line 879 PS C:\wamp64\www\laravel-demo>