To force all your traffic to HTTPS add the following lines of code inside your .htaccess file in your /public_html folder
Important: If you have existing code inside .htacess, add the lines in front of the rest of the code.
RewriteEngine On
RewriteCond %{HTTPS} off
RewriteRule ^(.*)$ https://%{HTTP_HOST}%{REQUEST_URI} [L,R=301]