With This Plugin you Easily insert QR codes in your blog, with Widget or Shortcode.
Could be a miolion thing but the main reason is you simply need to add the shortcode to a page or a post,
so simply create a page/post and enter
Simply use the Support Forum and thanks a head for doing that.
<?php echo do_shortcode('[QR]http://www.google.com[/QR]'); ?>