In order to complete the subscription, you must have a Carta Regionale / Nazionale dei Servizi (CRS), issued to all Italian citizens, or a Ricaricaev RFID card. If you don't have one, you can follow the instructions at this
Phone numbers must be inserted with international prefix (eg +39 for Italy).
SMS notifications will be sent only for italian numbers.
Carta Regionale dei Servizi
ID Code or Number: