How to run Koken on https?

Note that Koken is not running on the standard http and https ports 80 and 443.

After installing git, installed the letsencrypt certbot, but can't get it to run as expected. I'm trying this:

./certbot-auto certonly --test-cert --standalone --email someone@noreply.nl -w /apps/koken/web -d fotografeer.nl

But I get an error message:

The program apache2 (process ID 27035) is already listening on TCP
port 80. This will prevent us from binding to that port. Please stop
the apache2 program temporarily and then try again

If I stop apache and try again with:

 service apache2 stop

[ ok ] Stopping apache2 (via systemctl): apache2.service.

./certbot-auto certonly --test-cert --standalone --email someone@noreply.nl -w /apps/koken/web -d fotografeer.nl

I get the following error message:

Checking for new version...
Requesting root privileges to run certbot...
   /root/.local/share/letsencrypt/bin/letsencrypt certonly --test-cert --standalone --email someone@noreply.nl -w /apps/koken/web -d fotografeer.nl
Failed authorization procedure.
fotografeer.nl (tls-sni-01): urn:acme:error:connection ::
The server could not connect to the client to verify the domain :: 
Failed to connect to host for DVSNI challenge

IMPORTANT NOTES:
 - The following errors were reported by the server:

   Domain: fotografeer.nl
   Type:   connection
   Detail: Failed to connect to host for DVSNI challenge

   To fix these errors, please make sure that your domain name was
   entered correctly and the DNS A record(s) for that domain
   contain(s) the right IP address. Additionally, please check that
   your computer has a publicly routable IP address and that no
   firewalls are preventing the server from communicating with the
   client. If you're using the webroot plugin, you should also verify
   that you are serving files from the webroot path you provided.

Not very sure how to proceed from there.