Adding a PDF to the Documents section in NWBC for EHS module

Hello experts,

The requirement is to write a custom program so as to upload a PDF to the documents section in NWBC for the EHS module. We are able to add attachments during the creation of an incident but not able to add new attachments for the existing incidents.

As being new to the BOPF, I am not able to get the standard way of proceeding. Below is the screenshot of the documents section from NWBC. Are there any standard classes or function modules that can be used in this scenario?