1. Log in to your Plesk account.

2. Click on Websites & Domains from the Sidebar Menu.

plesk websites and domains menu

3. Click on Add Subdomain.

plesk add subdomain button

4. Enter a subdomain name and select a domain from the Domain field.

plesk add subdomain options

5. Click OK.

Once your Subdomain is added, you can manage it from Websites & Domains.