Answers for "flexbox in bootstrap4"

php artisan clear

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

php artisan clear commands

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

bootstrap display flex

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