You shouldn't be seeing this page, and it fully explains why you can't issue an SSL certificate.
This is usually a sign that something has gone wrong with the setup of your virtual host in cPanel.
What you should see is either your website, or the default index page of your web root.
Contact your web host to fix this, or if this is your cPanel server, try contacting cPanel support and ask them to investigate why your domain isn't showing its proper contents.