RewriteEngine On

# no www -> add www + https
RewriteCond %{HTTP_HOST} !^www\. [NC]
RewriteRule ^ https://www.%{HTTP_HOST}%{REQUEST_URI} [R=301,L]

# www, http -> https
RewriteCond %{HTTP:X-Forwarded-Proto} !https [NC]
RewriteCond %{HTTP:Forwarded} !proto=https [NC]
RewriteCond %{HTTPS} !=on
RewriteRule ^ https://%{HTTP_HOST}%{REQUEST_URI} [R=301,L]