FatalThrowableError in ServiceProvider.php line 49: Class 'Dompdf\Dompdf' not found

can i get some help to solve this problem, it works perfectly in my local, but in heroku i keep getting this error.

i tried:

heroku run php artisan cache:clear heroku run php artisan config:cache

But it did not work.

My providers, i am following the instructions to use Barryvdh\DomPDF:

'providers' => [

    /*
     * Laravel Framework Service Providers...
     */
    Illuminate\Foundation\Providers\ArtisanServiceProvider::class,
    Illuminate\Auth\AuthServiceProvider::class,
    Illuminate\Broadcasting\BroadcastServiceProvider::class,
    Illuminate\Bus\BusServiceProvider::class,
    Illuminate\Cache\CacheServiceProvider::class,
    Illuminate\Foundation\Providers\ConsoleSupportServiceProvider::class,
    Illuminate\Routing\ControllerServiceProvider::class,
    Illuminate\Cookie\CookieServiceProvider::class,
    Illuminate\Database\DatabaseServiceProvider::class,
    Illuminate\Encryption\EncryptionServiceProvider::class,
    Illuminate\Filesystem\FilesystemServiceProvider::class,
    Illuminate\Foundation\Providers\FoundationServiceProvider::class,
    Illuminate\Hashing\HashServiceProvider::class,
    Illuminate\Mail\MailServiceProvider::class,
    Illuminate\Pagination\PaginationServiceProvider::class,
    Illuminate\Pipeline\PipelineServiceProvider::class,
    Illuminate\Queue\QueueServiceProvider::class,
    Illuminate\Redis\RedisServiceProvider::class,
    Illuminate\Auth\Passwords\PasswordResetServiceProvider::class,
    Illuminate\Session\SessionServiceProvider::class,
    Illuminate\Translation\TranslationServiceProvider::class,
    Illuminate\Validation\ValidationServiceProvider::class,
    Illuminate\View\ViewServiceProvider::class,
    //Para configurar laravel Collective
    Collective\Html\HtmlServiceProvider::class,
    //Generar pdfs en la aplicacion
    Barryvdh\DomPDF\ServiceProvider::class,

    /*
     * Application Service Providers...
     */
    noMasTattut\Providers\AppServiceProvider::class,
    noMasTattut\Providers\AuthServiceProvider::class,
    noMasTattut\Providers\EventServiceProvider::class,
    noMasTattut\Providers\RouteServiceProvider::class,

],

/*
|--------------------------------------------------------------------------
| Class Aliases
|--------------------------------------------------------------------------
|
| This array of class aliases will be registered when this application
| is started. However, feel free to register as many as you wish as
| the aliases are "lazy" loaded so they don't hinder performance.
|
*/

'aliases' => [

    'App'       => Illuminate\Support\Facades\App::class,
    'Artisan'   => Illuminate\Support\Facades\Artisan::class,
    'Auth'      => Illuminate\Support\Facades\Auth::class,
    'Blade'     => Illuminate\Support\Facades\Blade::class,
    'Bus'       => Illuminate\Support\Facades\Bus::class,
    'Cache'     => Illuminate\Support\Facades\Cache::class,
    'Config'    => Illuminate\Support\Facades\Config::class,
    'Cookie'    => Illuminate\Support\Facades\Cookie::class,
    'Crypt'     => Illuminate\Support\Facades\Crypt::class,
    'DB'        => Illuminate\Support\Facades\DB::class,
    'Eloquent'  => Illuminate\Database\Eloquent\Model::class,
    'Event'     => Illuminate\Support\Facades\Event::class,
    'File'      => Illuminate\Support\Facades\File::class,
    'Gate'      => Illuminate\Support\Facades\Gate::class,
    'Hash'      => Illuminate\Support\Facades\Hash::class,
    'Input'     => Illuminate\Support\Facades\Input::class,
    'Lang'      => Illuminate\Support\Facades\Lang::class,
    'Log'       => Illuminate\Support\Facades\Log::class,
    'Mail'      => Illuminate\Support\Facades\Mail::class,
    'Password'  => Illuminate\Support\Facades\Password::class,
    'Queue'     => Illuminate\Support\Facades\Queue::class,
    'Redirect'  => Illuminate\Support\Facades\Redirect::class,
    'Redis'     => Illuminate\Support\Facades\Redis::class,
    'Request'   => Illuminate\Support\Facades\Request::class,
    'Response'  => Illuminate\Support\Facades\Response::class,
    'Route'     => Illuminate\Support\Facades\Route::class,
    'Schema'    => Illuminate\Support\Facades\Schema::class,
    'Session'   => Illuminate\Support\Facades\Session::class,
    'Storage'   => Illuminate\Support\Facades\Storage::class,
    'URL'       => Illuminate\Support\Facades\URL::class,
    'Validator' => Illuminate\Support\Facades\Validator::class,
    'View'      => Illuminate\Support\Facades\View::class,
    //terminando configurar laravel collective
    'Form' => Collective\Html\FormFacade::class,
    'Html' => Collective\Html\HtmlFacade::class,
    //Facade para generar PDFs
    'PDF' => Barryvdh\DomPDF\Facade::class,

],

And my composer.json:

"require": {
    "php": "^7.0",
    "laravel/framework": "5.1.*",
    "laravelcollective/html": "5.1.*",
    "guzzlehttp/guzzle": "~5.3|~6.0",
    "barryvdh/laravel-dompdf": "^0.8.1",
    "doctrine/dbal": "^2.5"

},

via Chebli Mohamed