OK, sorted this.
I still don’t see a way of doing this via the API without using the third-party plugin which seems to be unmaintained. Am I missing something? Is this something in development?
I have used advancedcustomfields.com/resources/update_field/ and this seems to give me what I need for now. I redirect to my new “Session” and add the ID of the parent “Project” to the URL (EG: ?parent=67) and use GET to pass this to the update_field function.
Cheers
Rob
