in config/app.php

add this :

 Nwidart\Modules\LaravelModulesServiceProvider::class,

    'providers' => ServiceProvider::defaultProviders()->merge([
        /*
         * Package Service Providers...
         */

        /*
         * Application Service Providers...
         */
        App\Providers\AppServiceProvider::class,
        // App\Providers\BroadcastServiceProvider::class,
        App\Providers\EventServiceProvider::class,
        App\Providers\RouteServiceProvider::class,
        Nwidart\Modules\LaravelModulesServiceProvider::class,
    ])->toArray(),