Answers for "please install the laravel/ui package"

composer require laravel/ui laravel 7

// Generate basic scaffolding...
php artisan ui bootstrap
php artisan ui vue
php artisan ui react

// Generate login / registration scaffolding...
php artisan ui bootstrap --auth
php artisan ui vue --auth
php artisan ui react --auth

composer require laravel/ui for laravel 6

composer require laravel/ui="1.*" --dev