Warning: require_once(../vendor/autoload.php): failed to open stream: No such file or directory in /var/www/html/lib/php-mailer/test/bootstrap.php on line 9

Fatal error: require_once(): Failed opening required '../vendor/autoload.php' (include_path='.:/usr/share/pear:/usr/share/php') in /var/www/html/lib/php-mailer/test/bootstrap.php on line 9