composer.jsonfile for editing in the root of the Magento 2 installation.
requirenode in the json file.
composer installfrom the appropriate user account that the Magento 2 installation is installed under.
It may be necessary to run the Magento 2 code compiler after the installation above is complete. eg, from the Magento root directory:
php bin/magento setup:di:compile
It also may be necessary to deploy static view files in your supported locales after installation is complete. eg, from the Magento root directory:
php bin/magento setup:static-content:deploy en_AU en_US
For more information about Composer, please visit https://getcomposer.org