RFID or radio frequency identification is a technology that can be used to identify yourself at a charging station. When you sign up, you can buy the RFID tag at the cost of 10 euros (incl. shipping). With this user specific RFID, you can use a charger without using the Virta app.
Where can I get myself RFID tag and card?
If you chose not to order the RFID tag during the registration but later changed your mind, don't worry. You can still order the tag in the Virta app.