sitegen/apache/letsencrypt.conf

<IfModule mod_proxy.c>
<Location "/.well-known/acme-challenge/">
    ProxyPass "http://127.0.0.1:9999/.well-known/acme-challenge/" retry=1
    ProxyPassReverse "http://127.0.0.1:9999/.well-known/acme-challenge/"
    ProxyPreserveHost On
    Order allow,deny
    Allow from all
    Require all granted
  </Location>
</IfModule>