Under Force HTTPS Redirection click on the switch to turn it on for your domain name (Note: cPanel won’t let you turn this option on if you don’t have an SSL certificate installed).
If this hasn’t worked for you, the most reliable way to ensure your site loads securely is by adding the following code to the top of your .htaccess file:
`# START Force HTTPS
RewriteEngine On
RewriteCond % !on
RewriteRule (.*) https://%% [L,R=301]