Not all carriers call the recipient before delivering because they do not always have a company phone. In the case of standard shipping services, the courier is not actually obliged to call before delivery.
When you book your label, you are still required to indicate the recipient's telephone number, in case it is needed.
The telephone is particularly useful for international shipments, in such cases please remember to always enter a local phone number.
For example, if you send a parcel to Germany, you will need to enter a German telephone number for the recipient. If you enter an Italian number, the carrier will not make the call.
It is not necessary to enter the international prefix for foreign numbers since it is already present automatically in the online booking system.