There is no any functionality related to QR code in Open CASCADE Technology, as far as I know.
So you need to create a 2D contours (shapes) for your QR Code somehow and than general algorithms like extrusion can be used for generating 3D shape.
Considering structure of QR Code, if you have correct Bitmap for it (e.g. generated using some library, not captured photo),
than you can create a 3D box for each black pixel in the image as most simple solution.