The code does not scan.
Hold the phone 4 to 8 inches (10 to 20 centimeters) away in good light, and let the camera focus — the code is half an inch across. If it still will not read, type the short address printed beside it into a browser.
From the guide Receipts, Notices & Statements.
The code in the corner
Every PDF Seayora draws carries a small QR code in the bottom-right corner of every page, with a short address beside it (seayora.com/d/ followed by a few letters and numbers). Point your phone’s camera at it and it opens that same document in your Seayora account — in the Seayora app if it is installed, on seayora.com if it is not. If you are signed out, you are asked to sign in and land straight back on the document. You can also type the short address into a browser, or scan it with the scanner inside the Seayora app.
The code is a pointer, not a key. It opens the document only for an account that can already see it — the same rule as opening it from Documents — so somebody who photographs your receipt and scans it is told only that the document is not in their account, exactly as if it did not exist. A page that was later replaced says so when you open it, with a button to the current version; a withdrawn one says it was withdrawn.
Read the whole guide: Receipts, Notices & Statements