A subdomain is an additional part of your primary domain. Please, follow this tutorial to remove a subdomain in Plesk.

1. Log in to your Plesk account.

2. Click on Websites & Domains from the Sidebar Menu.
How to Remove a Subdomain in Plesk - 2024

3. Under the list of Domain names, click on the More icon How to Remove a Subdomain in Plesk - 2024 in front of the subdomain and select Remove subdomain.
How to Remove a Subdomain in Plesk - 2024

4. Confirm with Yes to remove the subdomain.