If you right-click on the preview screen of the QR code generated by the QR output function and select 'Save image as', the QR code may blend into the background color of the pasting destination, making it unreadable.
Please try one of the following methods to ensure the QR code can be scanned properly:
- Set the background color of the pasting destination to white
- Download the QR code image data from 'Download QR code'
Related: Export manual QR code (Web Browser)
https://teachme.jp/8/manuals/5619038
Related: Is there a recommended print size for manual QR codes?
https://help.teachme.jp/hc/en-us/articles/4402384411161