It is important that the entire label is visible to the camera.
Also, no other QR codes should look into the camera, except the QR code you want to scan.
The easiest way is for the camera to recognize the QR code from the test code label before it is sticked to the test tube.
If the camera still does not recognize the test code label, it is possible to enter the number of your test code label manually.
The following numbers must be entered: