A card reader is a stand-alone device and has nothing to do with any web tech.
You put your ATM card in the device, enter your PIN code, and then the device has a tiny camera that scans the QR code on the web page. Next, you can see the transaction details on the device and confirm. It will then output a signing code which you enter on the web page.
It is what was commonly used in some EU countries before we switched to mobile banking apps. Most banks still supply them for when you do very large online transactions.
You put your ATM card in the device, enter your PIN code, and then the device has a tiny camera that scans the QR code on the web page. Next, you can see the transaction details on the device and confirm. It will then output a signing code which you enter on the web page.
It is what was commonly used in some EU countries before we switched to mobile banking apps. Most banks still supply them for when you do very large online transactions.