I know this is a couple of years old now, but I’m trying to do the same thing. @marieke_louise did you manage to locate the id of the event post, as per John’s answer? Where did you place the acf_form function? Could you share a sample of the code for adding the groups and fields into the edit-event form please? is this all working for you OK now or has this project moved on?
I’ve probably complicated things by using ACFE forms, that show up OK in the form, but I can’t save the contents at all. I’ve tried your code above, but can’t locate the form id in $_POST.
Thank you.
