Thanks, James! I’m very happy now 😀
This is what I figured out: I have a functionality plugin to keep my added code in one place. In my plugin, I put
add_action('admin_menu', 'acf_add_options_page');
if( function_exists('acf_add_options_page') ) {
acf_add_options_page();
}
What I was missing before was the add_action part. This is not at all clear in the user guide (well, it wasn’t to me.)
Now I can make helpful controls for my users <does a silly dance>