Drupal console installation

Hi, I juste can’t have drupal console up and running, after folowing the instructions here https://drupalconsole.com/ for exemple: drupal site:new – v return [SymfonyComponentConsoleExceptionCommandNotFoundException] There are no commands defined in the “site” namespace. Exception trace: () at phar:///usr/local/bin/drupal/vendor/symfony/console/Application.php:475 SymfonyComponentConsoleApplication->findNamespace() at phar:///usr/local/bin/drupal/vendor/symfony/console/Application.php:507 SymfonyComponentConsoleApplication->find() at phar:///usr/local/bin/drupal/vendor/symfony/console/Application.php:189 SymfonyComponentConsoleApplication->doRun()[…]