سلام
RewriteEngine On
RewriteCond %{HTTPS} off
RewriteRule (.*) https://%{HTTP_HOST}%{REQUEST_URI} [R,L]
یا:
RewriteCond %{HTTPS} !=on
RewriteRule ^.*$ https://%{SERVER_NAME}%{REQUEST_URI} [R,L]
یا:
RewriteEngine On
RewriteCond %{SERVER_PROTOCOL} ^[^https]$ [NC]
RewriteRule ^(.*)$ https://domain.com/$1 [R,L