I had the need to create a QR Code with a transparent background in order to avoid my background color not quite matching the color of an invitation. That led me to the QR Code generator at the link below. If you scan the QR Code in the image below, it will take to you to www.paulishing.com, a page that lists all the various blogs I write and a couple of demos.
The dark blue background is part of a Google Slide and I inserted my transparent QR Code on top of it and then took a screenshot. And as you can see, you can use hearts, among many options, to make the code more interesting.