Redirect non-www and non-http to https

RewriteEngine on


RewriteCond %{HTTPS} off [OR]
RewriteCond %{HTTP_HOST} !^www\.
RewriteRule ^ https://www.example.com%{REQUEST_URI} [NC,L,R=301,NE]

This will redirect both http or non-www to https://www

Use:

RewriteCond %{HTTPS} off
RewriteCond %{HTTP_HOST} !^www\.
RewriteRule .* https://www.%{HTTP_HOST}%{REQUEST_URI} [L,R=301]

OR you can try:

RewriteEngine On 
RewriteCond %{HTTP_HOST} ^example\.com [NC]
RewriteCond %{SERVER_PORT} 80 
RewriteRule ^(.*)$ https://www.example.com/$1 [R,L]