An SSL certificate on your website has many benefits it provides a secure, identity-validated, and encrypted browsing experience for your customers.

This video explains how to activate Let’s Encrypt SSL certificate on your website from cPanel.

Code to add in .htaccess file:
RewriteEngine On
RewriteCond %{REQUEST_FILENAME} !-f
RewriteRule ^([^.]+)$ $1.php [NC,L]

You can also read an in-depth guide here: https://www.milesweb.com/hosting-faqs/how-to-activate-lets-encrypt-ssl-certificate-for-your-website/