Вы можете использовать:
RewriteCond %{HTTP_HOST} !^www\. [OR,NC]
RewriteCond %{HTTPS} off
RewriteRule ^ https://www.exemple.com%{REQUEST_URI} [NE,R=301,L]
или без доменного имени:
RewriteCond %{HTTP_HOST} !^www\. [NC]
RewriteRule ^ https://www.%{HTTP_HOST}%{REQUEST_URI} [NE,L,R=301]
RewriteCond %{HTTPS} off
RewriteRule ^ https://%{HTTP_HOST}%{REQUEST_URI} [NE,L,R=301]