To Add Domain Alias in Plesk, please follow the following settings:-
1) Login to Plesk control panel.

2) Click on Websites & Domains.

3) Click on Add New Domain Alias

4) Type Domain alias name as marked in RED.

5) Click Ok.
Information: The domain alias domainalias.com was created.
![GRABWEB [India] GRABWEB [India]](/templates/lagom2/assets/img/logo/logo_big.454175622.gif)