Failed to compile with 2 errors in ./resources/sass/app.scss

I want to create authentification system in laravel 6

after these commandes:

composer create-project laravel/laravel=6.0 ecommerce-laravel --prefer-dist
composer require laravel/ui="^1.0" --dev
php artisan ui vue --auth
npm install && npm run dev

i get this error :

via Chebli Mohamed