Jrack Wolfe

Displays at QR code dynaically on a page or post with URL to that page/post.
There are many QR generators that are avialable for use. Most of these, however, are accessbile via the admin dashboard so you can create site QR codes as media files for download. This plugin also does that but goes one step further – it allows you to use shortcode to dynamically generate a QR code for the page or post being displayed.
Wolfe Candy QR Code Generator is part of the Wolfe Candy suite of plugins that all work together to make <a href="https://wordpress.org/" title="Your favorite software" rel="ugc">WordPress</a> site creation that much easier. The QR code generator works particularly well with the Wolfe Candy S3 Gallery.
Major features include:
<ul>
<li>This dynamically generates a QR code in the front-end for the page or post that is being displayed via shortcode.</li>
<li>This plugin uses the standard PHP generator library so it can also generate a QR code to a file.</li>
<li>It can also generate a QR code for any data text via shortcode.</li>
<li>Alter size, error correction and pixel scale via shortcode arguments.</li>
<li>It is a simple QR code generator so does not support different color styles and logos – it just does what is needs to do.</li>
</ul>
It is completely FREE – development and maintenance by the Wolfe Candy team headed by Jrack Wolfe is funded through <a href="https://www.paypal.com/donate/?hosted_button_id=DY2RMD3J4SR3Q" title="Donate to Wolfe Candy" rel="nofollow ugc">donations</a> from generous users.

Wolfe Candy QR Code Generator

Displays at QR code dynaically on a page or post with URL to that page/post.

aklamator

It also enables you to place dynamic QR codes using widget. Dynamic QR codes are easier to scan and enable you to track number of scans, device type, and change URL destination.
How to auto generate QR codes for each post/page
Open plugin settings and choose static QR code (for simple QR codes without analytics). Each page/post will have unique QR code redirecting user which scans it to that page. 
If you create free CodeQRCode account and paste ApplicationID, dropdown list will show your dynamic QR codes also.
Checkout how to create QR code contact vcard and place it :
<iframe loading="lazy" class="youtube-player" width="750" height="422" src="https://www.youtube.com/embed/EqfTHkPVPoY?version=3&rel=1&showsearch=0&showinfo=1&iv_load_policy=1&fs=1&hl=en-US&autohide=2&wmode=transparent" allowfullscreen="true" style="border:0;" sandbox="allow-scripts allow-same-origin allow-popups allow-presentation allow-popups-to-escape-sandbox"></iframe>
How to place AdSense ad code ? 
Just copy & paste AdSense or any other third party Ad code to box and optionally add name. Choose default Ad for each post and page. Go to Dashboard > Appearance > Widgets and Drag n Drop desired code to desired position. Thats it!
Advantages of Dynamic QR codes:
<ol>
<li>Easier to scan (because codeqrcode uses short URL)</li>
<li>Ability to change URL later (after placing it on your web site or printing it) – by using codeqrcode dashboard you can change destination URL whenever you want.</li>
<li>Scan analytics – using codeqrcode dashboard you can have insight in number of scans, device types used to scan, whether the scan is new or returning, date, time and much more…</li>
</ol>
You can read more about <a href="https://www.codeqrcode.com/blog/dynamic-vs-static-qr-code/" rel="nofollow ugc">dynamic vs static QR codes</a>

QRCode Generator – Adsense

CodeQRCode plugin enables you to automatically generate QR codes on each post and page on your wordpress site. Bonus: You can easily include your AdSe …

Wolfe Candy QR Code Generator vs QRCode Generator – Adsense