Staples. It's (not) easy.

Staples has an app. All God's children have an app.
The Staples app purports to let us do things, except the things that seem obvious.
Each time I buy something at Staples, I can't find my card, the loyalty card that enables coupons and discounts. .I provide them with my phone number. They look up the card and apply the credit, if anything, to my purchase.
This last time, I thought I'd be clever. The app lets me store my Staples reward card. I did so.
When I went to check out at the store, I hold up the app, displaying the barcode and number.

The clerk looks at my phone and then enters my number by hand because their scanner cannot pick up the barcode stored on their app.
One less reason to use their app on the way to one less reason to shop at Staples.