Basics
PHP Composer is pre-installed on our shared hosting servers and is included in the hosting package. You can access it directly via ‘composer’.
PHP Composer - Specifying the PHP version
Alternatively, you can also specify a particular PHP version for PHP Composer by entering the full path to the desired PHP version.
To do this, follow the instructions in the following help article: How do I access different PHP versions via SSH?
PHP Composer - Using your own php.ini
To use your own PHP configuration with Composer, you can also specify the account-specific php.ini file at the command line.
To do this, follow the instructions in the following help article: How do I use my own php.ini / PHP configuration via SSH?