Append the following lines in your .htacess file.
RewriteEngine On
RewriteCond %{SERVER_PORT} 80
RewriteRule ^(.*)$ https://www.example.com/$1 [R,L]
To force a specific domain to use HTTPS, use the following lines of code in the .htaccess file in your website's root folder:
RewriteEngine On
RewriteCond %{HTTP_HOST} ^example.com [NC]
RewriteCond %{SERVER_PORT} 80
RewriteRule ^(.*)$ https://www.example.com/$1 [R,L]
If you want to force SSL on a specific folder you can insert the code below into a .htaccess file placed in that specific folder:
RewriteEngine On
RewriteCond %{SERVER_PORT} 80
RewriteCond %{REQUEST_URI} folder
RewriteRule ^(.*)$ https://www.example.com/folder/$1 [R,L]
Note:Dont't forget to replace
www.example.com with your actual domain name