Send documents via the B2B API

The PN services offer notification forwarding APIs. Sending takes place in two phases. During the first phase, the attachments are uploaded (documents and payment forms). During the second phase, the request to send the notification is forwarded, providing all the necessary information, including the references to documents previously uploaded to the platform and their hash SHA-256 calculated by the PA and used by NP to confirm the content of the attached file. If the information provided for the notification is syntactically correct, NP returns a temporary identifier that will be used by NP to transmit the result of additional and further checks to the PA. At this point, NP verifies that all files are available, are in PDF format and have been digitally signed by the PA. It also verifies the existence of the fiscal codes produced by the PA and the existence of a physical address for each recipient. If the verification operation is successful, an IUN is generated that is returned to the PA together with the previously generated temporary identifier. Otherwise, an error code will be sent, together with the temporary identifier, that indicates the reason the verification failed. From the moment a notification was created successfully, the PA will receive updates about its status by means of an intelligent polling mechanism provided by NP. Each status update will contain the IUN of the notification to which it refers.