How to install Let's Encrypt certificate for domain alias?
A separate certificate for the alias only cannot be created. Create a new Let's Encrypt certificate for its domain and specify the alias to secure during the creation.
I. Install Let's Encrypt from Extensions catalog if it is not yet installed.
II. Create a new certificate:
- Go to Websites & Domains > Let's Encrypt.
- Specify the email address.
- Specify if you want to include an alternative domain name for the domain and each selected alias, for example:
www.example.comfor example.com. It is recommended to select this checkbox.
- Specify if you want to include webmail, for example:
webmail.example.com. It is recommended to select this checkbox.
- Select the domain alias to secure and click Install.
III. Secure the main website with it's aliases:
- Go to Websites & Domains and click Hosting Settings.
- Select the SSL/TLS support checkbox.
- Select the Let's Encrypt certificate you have just issues from the Certificate menu, and click OK.
Note: To secure a domain alias with a certificate purchased from one of the certificate authorities, contact the certificate provider in order to add the alias name to the certificate as the subject alternative name (or SAN). Then, secure the main domain with this certificate as described in the article How to install SSL certificate for a domain in Plesk.