Installation Requirements Installing your Let's Encrypt SSL certificate Your site, domain and subdomains must point to your hosting account. Log into your cPanel.In the "Security" tab, click on "Let's Encrypt SSL"Select the domain name you would like to install the certificate on.Choose the Alias Domains you'd like to install the certificate on, in addition to the main domain. You can also install mail SSL certificate here.Click on "Issue". This can take up to 2 minutes.Your SSL certificate has been successfully installed!