Preview option allows visiting the site before DNS has propagated:
Domains > example.com > Preview
It opens the domain on a URL:
where 10.10.10.10 is the Plesk server IP
This URL does not require a user to log in to the Plesk interface.
The contents of password-protected directories might be inaccessible in the Preview mode.
For more details, visit Plesk Administrator Guide.
Note: Plesk works as a proxy in this case, to make sure that the domain name is resolved to the local IP address (that the domain is configured with) from the Plesk server itself.
Another way to preview a site is to add the records for the domain to the
hosts file in your system. It is
/etc/hosts on Linux and
C:\windows\system32\drivers\etc\hosts on Windows. The record should look like this:
10.10.10.10 example.com www.example.com