The card readers have an LCD display that shows the information.

How do they get this information in the first place, though? Do they have a QR code reader?

	▲	sdl a day ago \| parent [-]
		Yes, in that case it's often called Photo-TAN or QR-TAN. See https://en.wikipedia.org/wiki/Transaction_authentication_num... Previously there were also so called "flicker TAN" approaches: https://de.wikipedia.org/wiki/Transaktionsnummer#chipTAN_com...