how to include env variables in larvel blade code example

Example: laravel 5 use env variable in blade

Five most important commands if your Laravel is not working as expected after 
some modifications in .env or database folder or because of any other modifications. 
Here is full explanation: https://www.youtube.com/watch?v=Q1ynDMC8UGg

php artisan config:clear
php artisan cache:clear
composer dump-autoload
php artisan view:clear
php artisan route:clear

After clearup, try "echo env('URL_BUILDER')"