PIH issue about invoice sign

Signing process
1

I have a question regarding PIH, Do i Have to save it for use in next invoice or it will create for me??

2

Ensure that the Invoice Hash is saved, as it will be required for the PIH in the subsequent invoice

3

Dear @sayedrahman,

ZATCA will not provide you the PIH element of your XML.

Your solution (EGS) must be able to assign the invoiceHash of the last generated XML in the PIH element of the newer generated XML.