nano antonini.ddns.net.conf

<VirtualHost *:80>
    ServerAdmin vladimir@antonini.com.br
    ServerName antonini.ddns.net
    DocumentRoot /var/www/html/blogmed/
    ErrorLog ${APACHE_LOG_DIR}/error.log
    CustomLog ${APACHE_LOG_DIR}/access.log combined
</VirtualHost>

a2ensite antonini.ddns.net.conf

systemctl reload apache2