Purchasing 12.2 Cancel PO API

Hi, not sure if this is the right forum, but I want to know if there´s an update for Purchasing version 12.2 of the API for cancelling a PO, I´ve already searched for the documentation in MOS, and have been using the info in the document:

Vision Demo - How To Use the Cancel PO API (Doc ID 1077153.1)

But when I run the code in SQL Developer (screenshot #4) to cancel the whole PO (PO #29 in my case, screenshot #1), including setting my context data (user_id, responsibility_id and application_id), and the data of the PO to cancel (po_header_id as the p_doc_id, and po number as p_doc_num) (screenshots #2 and #3), it ends without errors, but don´t cancel the PO (and of course, committing the changes). (screenshoot #5)