1. Log in to your Plesk account.
2. Click on Websites & Domains from the Sidebar Menu.
3. Under the list of Domain names, click on the 
Hosting Settings icon appearing in the same row of the subdomain.
4. Enter the following details:
- Hosting Type: Choose the Forwarding option from the drop-down menu.
- Forward visitors to: Enter the link to which you want to redirect the subdomain.
- Forwarding Type: Choose it according to your need.
5. Click Save. Read the warning and confirm it with Yes.