Requiring the WWW

hi

I want to force my wordpress website to https://www.domain.com instead of domain.com.

I have added this in to my .htaccess file:

Options +FollowSymLinks
RewriteEngine On
RewriteBase /

# require non-empty HOST header
RewriteCond %{HTTP_HOST} !^$

# require case-insensitive HOST to be www.domain.com
RewriteCond %{HTTP_HOST} !^www\.domain\.com$ [NC]

# 301 redirect everything to correct www.domain.com
RewriteRule ^(.*)$ https://www.domain.com/$1 [R=301,L]

But i get Redirect Loop.

Please help me to fix this.

thanks