It’s 2026, why can’t credit card and merchant figure out a way to transmit order summary URL as part of credit card transactions so I don’t need to match up transactions by amount??
A similar thing as what you propose already exists in the Nordics. You pay with your card as normal, and the receipt gets logged automatically in the app.
https://en.storebox.com/#/
Not universally supported unfortunately, but the major stores support it.