Apesar do acesso ao DirectAdmin ser feito via http://www.seusite.com.br/config, os comandos abaixos habilitar endereços /webmail, /whm e /cpanel
echo 'Alias /webmail /var/www/html/roundcube' >> /etc/httpd/conf/extra/httpd-alias.conf
echo 'Alias /whm /var/www/html/redirect.php' >> /etc/httpd/conf/extra/httpd-alias.conf
echo 'Alias /cpanel /var/www/html/redirect.php' >> /etc/httpd/conf/extra/httpd-alias.conf
Restart do serviço http:
service httpd restart
systemctl restart php-fpm*