When I realized letsencrypt is an option in Virtualmin, I tried installing it that way using these instructions:
But it halted on this error:
Validating configuration for myvirtualserver.com …
… errors were found, which will prevent Let’s Encrypt from issuing a certificate :
Apache website : PHP is configured to run as the domain owner, but SuExec is not enabled!
I’m not sure if this is relevant, but in the previous step (enabling SSL for the site) I had to edit “/etc/apache2/sites-enabled/myvirtualserver.com.conf” and replace
VirtualHost ipv4address:80
with
VirtualHost *:80
or all the sites would point to myvirtualserver.com.
Also, before I realized it was an option in Virtualmin I went through the manual installation as far as "apt-get install certbot python-certbot-apache ".