Are you Dutch? I recall an old NJB video describing how Dutch supermarkets worked like this. (Plus, Martin is a name I associate with the Netherlands…)
But no. Most often, you put stuff in your trolley or basket, then when you get to the checkout, you scan the things and bag them yourself one-by-one, then pay.
Here in Australia, one of our two main supermarket chains in the last 2 years rolled out something similar to what the Netherlands has had for at least half a decade. You use their app on your phone and scan things with the app as you go, before paying through the app and scanning a QR code at the exit.
The other main chain, and the two main smaller chains, have made no moves to follow, so you’re stuck with a long line for a small number of open checkouts, or the self-checkout where you have to scan everything after you get to the checkout.