composer require laravel/ui --dev code example
Example 1: composer require laravel/ui laravel 7
composer require laravel/ui:^2.4
Example 2: composer require laravel/ui app.css empty
Try remove folder node_modules,
then run this again:
npm install
Make sure installation done without error
and then compile again using:
npm run prod
Example 3: composer require laravel/ui for laravel 6
composer require laravel/ui="1.*" --dev