It is not possible to add a QR code to a virtual combination. The reason for this is that we consider those combinations to be a flexible combination of items that can be rented out together, but can also be rented out separately.
A good example is a virtual combination containing speakers, subwoofers, and full-range cabins. You will mostly rent them out together, but sometimes you want to rent them out individually.
You can, however, assign QR codes to a physical combination of items. In this article, you can learn more about both combination types and accessories.