If the terminal reports error 3003 or 3004, it is not connected to the banking institution's service server and the transaction cannot be performed. At the moment, the terminal is either disconnected from the wi-fi network, is stuck or it is an error directly on the bank's server.
Try restarting the terminal and make sure it is connected to the Internet. In case of persistent problems, you can contact the bank's service. If this problem persists, it is quite likely that these are Internet problems.