wp_update_post() no purge

I have a website that uses an API to place,update & delete custom posts which uses wp_update_post().
Unfortunatly this does not trigger a purge. So instead I use a curl function that uses the *domain*/purge/*slug.
But even then the purge doesn’t occur most of the time.
Isn’t there a function I can use (maybe giving a post_id with it) to purge a specific custom post?