How to Force Your Website to Use HTTPS in cPanel
cPanel · Self-help guide
After SSL is installed, you may want visitors to automatically use the secure HTTPS version of your website. Log in to cPanel and open Domains. Find your domain in the list and look for the Force HTTPS Redirect option. Turn it on for the correct domain. Next, visit your website using http:// and confirm that it redirects to https://. If the option is not available, the redirect may need to be added to the site configuration or .htaccess file. Do not edit .htaccess unless you are comfortable doing so. If your website shows mixed content warnings, update images, scripts, and links to use HTTPS.