//Install the package
composer require barryvdh/laravel-debugbar --dev
//change 'config/app.php' file
//in 'providers' section, paste this line:
Barryvdh\Debugbar\ServiceProvider::class,
//in 'aliases' section, paste:
'Debugbar' => Barryvdh\Debugbar\Facade::class,
//Then publish the component
php artisan vendor:publish --provider="Barryvdh\Debugbar\ServiceProvider"
//And make sure that the .env variable 'APP_DEBUG' value is 'true'.
//That's all