QR codes are digital information which will be stored in image format. Many people are showing the QR code image in there site. You can very easily show the chart qr image in your post.
Show QR code in your wordpress post
You need to use the following code in your single.php file.
<img src="https://chart.googleapis.com/chart?cht=qr&chs=250x250&chl=<!--?php the_permalink(); ?-->" alt="QR: <!--?php the_title(); ?-->"/>
