Get SSL certificate via LetsEncrypt
letsencrypt certonly --webroot -w /var/www/html -d html.citysports.de.staging.ext.dev
Configure Apache vHost
vi /etc/apache2/sites-available/html.citysports.de.staging.ext.dev.conf
a2ensite html.citysports.de.staging.ext.dev.conf
sudo service apache2 restart