From the official site....

Notts County supporters attending Saturday's trip to Lincoln City are asked to check they have a QR code attached to their ticket.
Due to an administrative error, a small number of away tickets were sold without the code (see photograph in link below), which will need to be scanned at the turnstile at Sincil Bank.

https://www.nottscountyfc.co.uk/news...ets-lincoln-a/