Cypth is a modern webmail interface.
as user web get/install composer. The following is copied from here:
su - web php -r "copy('https://getcomposer.org/installer', 'composer-setup.php');" php -r "if (hash_file('sha384', 'composer-setup.php') === 'dac665fdc30fdd8ec78b38b9800061b4150413ff2e3b6f88543c636f7cd84f6db9189d43a81e5503cda447da73c7e5b6') { echo 'Installer verified'.PHP_EOL; } else { echo 'Installer corrupt'.PHP_EOL; unlink('composer-setup.php'); exit(1); }" php composer-setup.php php -r "unlink('composer-setup.php');"