Answers for "bootstrap 4 flex bos example"

laravel clear cache

php artisan cache:clear
php artisan route:clear
php artisan config:clear 
php artisan view:clear

clear cache in laravel without artisan

Route::get('/clear-cache', function() {
     $exitCode = Artisan::call('cache:clear');
     return 'Application cache cleared';
 });

bootstrap display flex

<div class="d-flex">I'm a flexbox container!</div>