Connection not secure error on non-www domain

hostname: www.prijavite.ba

I am having an issue where when entering “prijavite.ba” on somebrowser (i.e. firefox) a error is shown that the connection is not secure.

I believe this is because there is an automatic HTTPS redirect from HTTP but the website’s LetsEncrypt certificate is only valid for the www version of the site. I am using the automatic LetsEncrypt certificate from the Admin area.

Am I doing something wrong with my configuration? I understood that the hostname should be the full URL with www. Perhaps the non-www domain should be added automatically as an alias to the certificate? I believe this is the SAN feature which they should support.

Appreciate your support on this issue!

Kind regards,
Vojta