On an iPhone 13, you can scan paperwork directly from Notes without installing a separate scanner app.
- Open Notes and open the note where you want the scan stored.
- Tap the camera or attachment button.
- Choose Scan Documents.
- Position each page inside the camera view and capture it, adjusting the corners when necessary.
- Tap Save after the final page.
If by scan you mean a QR code rather than a paper document, open Camera and point it at the QR code instead; that uses a different feature.
After completing the steps, check the result for Scan on iPhone 13 before changing another setting. If it did not work, return to the same control and review the selected option rather than making a broader reset.