If your hosting package includes subscriptions (third-level domain names), you can use them to logically organize the structure of your site or host additional websites or parts of websites on the same server without needing to pay for other domain names.
Because subdomains have the same status as additional domains, you can use the same set of tools/services to work with them, including web statistics, SSL/TLS protection, Presence Builder, and more.
How to set up a subdomain for a site division or separate site
2. Click on Websites & Domains.
3. Click Add Subdomain.
4. In the Subdomain name box, type the portion of the address that will be added to the domain name of your main site.
5. In the Document root box, type the desired location of the directory where files and subscriptions will be stored. You can use the default directory (httpdocs) or specify another directory.
6. Click OK.
The new subdomain will be shown at the list at the bottom of the screen. You can now upload your web content to the subdomain.
How to create a wildcard subdomain
Enter the asterisk symbol (*) as a subdomain name, and Plesk will create a wildcard subdomain. When site visitors enter a subdomain not registered in Plesk, they’ll be redirected to the wildcard subdomain. Wildcard subdomains can be created on any domain name level.
If you need help with Plesk, please open a support ticket from your dashboard.