When booking a SHARE NOW vehicle, your payment method will be authorized for the amount of 20 EUR. However, this amount will not be charged at first, but merely blocked. You will only be charged if you actually complete your trip and, of course, only for the amount corresponding to the duration of your booking.
Please be aware, that the unblock of the authorization amount can take a few days depending on your bank.
The authorization process is a security feature that confirms the validity of your payment method.