A. Ensure that the camera lens is clean and unobstructed. Open the app and navigate to the rewards section. Try scanning the receipt in a well-lit area, holding the receipt flat and steady. If it still fails, check if the app has any updates available in the Google Play Store and install them. Restart the app after updating.

B. If scanning continues to fail, manually enter the receipt details if the app provides that option. Look for a 'manual entry' or 'enter receipt' button in the rewards section.