Your customers can preview their websites during domain name propagation. The two preview modes are available: Quick Preview and Limited Preview.
Quick Preview, the recommended option, presents customers' sites as subdomains of one of your domains. For example, customer-site.tld will be available for preview as customer-site.tld.192-0-2-12.your-domain.tld. Here 192-0-2-12 is the site's IP where dots are replaced with dashes. Note that if you do not specify a preview domain, the site preview function will be unavailable to your customers.
(Default) Limited Preview is used in earlier Panel versions; it presents customers' sites as directories under the Panel server. For example, server-host-name:8443/sitepreview/http/your-domain.tld/. This mode has two major drawbacks: Only authorized users can view such websites and some scripts and Flash animation might not work well on them. We recommend to use this mode only before the Quick Preview is configured.
The preview selector and the form to configure the preview domain name is located in Tools & Settings > Website Preview Settings.
Note: Customers also could preview their sites prior to Panel 10.4, but the preview feature had a number of limitations due to different implementation methods.The major difference is that since 10.4 customers can share the preview link with anybody, whereas previously they could only view the domain themselves. In addition, sites in the earlier preview mode would not work with complex CGI scripts or Flash content.