How to add hosting for a subdomain in your Plesk control panel
1. Login to Plesk control panel.
2. Click on Subscriptions in the left hand pane and then select the subscription you would like to add the subdomain to.
3. Click the Add Subdomain button.
4. Type the new subdomain same as marked below and type in a folder name for the subdomain website to run from.
6. Click Ok.