How do I Install an earlier version of Drupal 8 with composer because install fails on server with PHP 5.6? My server is using PHP version 5, therefore, I need to install Drupal 8 version 8.6.18. But when I try, composer create-project drupal-composer/drupal-project:8.x-dev my_site_name_dir --no-interaction --no-install, I get the following error. 

  [InvalidArgumentException]                                                   
  Could not find package drupal-composer/drupal-project with version 8.x-dev   
  in a version installable using your PHP version 5.6.40.  


Is there anyway to install 8.6.18 with composer?
Drupal 8 does not support PHP version 5. It requires a minimum PHP version of 7.0. Please see here for Drupal install requirements

Drupal Installation Requirements - Drupal.org

So you will have to upgrade PHP on your machine. Also PHP 5.0 is no longer supported and is not secure. So you might want to upgrade PHP on your server any way.

PHP Supported Versions - php.net