So here is my error...
Requesting a certificate for ajecreative.com.au, *.ajecreative.com.au from Let's Encrypt ...
.. request failed : Web-based validation failed : Wildcard hostname *.ajecreative.com.au can only be validated in DNS mode
I note the following on github...https://github.com/webmin/webmin/issues/838
I had a quick look, and actually this isn't totally trivial - wildcard certs can only be requested with the ACMEv2 protocol, and also only via DNS validation(which Webmin does support, but which won't work for users that don't host their own DNS).
which is unfortunately me (ie i dont host my own nameservers)
So, how do i get a virtual server ssl certificate to share with a subserver? (my webmin/virtualmin system is currently not doing this)