You will need an SSL Certificate to log in securely to WHM, cPanel, and webmail. You can purchase a signed certificate from an SSL certificate provider with the name of your choice, for example, secure.primarydomain.com or login.primarydomain.com. To install and manage the service certificate,

1. Log in to the WHM by going to yourdomain.com/whm in a browser. Replace yourdomain.com with your domain.
2. Once you get to the login page, enter your username and password.
   • Username will be root.
   • Password will be the root password for your server.
     
3. If this is your first time logging into the WHM, you may see a page titled Feature Showcase. Click on Exit to WHM at the bottom of the page.
   
4. In the WHM Search box on the left side, enter Service Configuration.
5. Click on the Manage Service SSL Certificates from the list.
   
6. For the Calendar, cPanel, WebDisk, Webmail, and WHM Services, click Apply Certificate to Another Service under Actions.
   

   Note: When you purchased the certificate, you received three files. Please ensure you have all three files before continuing.

7. Paste the .crt file in the space provided, and click Browse. The subdomain name will be displayed. 
8. Paste the content of the .key and the CA bundle files in the spaces provided.
9. Scroll down and click Submit.
10. In the Server Configuration section, click Tweak Settings.
    
11. Click the Redirection tab.
    

    Note: Make sure the always redirect to SSL option is set to On.

12. Click Save.