So, I have a repeater field which my site users will be able to use on the frontend using acf_form() to add rows to the repeater. This form appears on a WooCommerce order details page

ACF Form works fine, rows get added etc and saved to the order. Cool.

Now, one of the fields in the repeater is an email address. Here’s what I’m hoping I can get to happen:

1. User adds rows to the repeater on the frontend and submits the acf_form()
2. When the repeater is saved OR updated on the frontend, the email addresses in the email sub field get an email notification (I can format the email myself later), but only the updated rows/fields

This action needs to be triggered EVERY TIME the form is changed and submitted on the frontend

Hopefully this is possible

Here’s kind of what I have from another support post I stumbled on from Google:

function delegate_form_update($value, $post_id, $field) {

    // only do it to certain custom fields
    if($field['name'] == 'ticket_alloc') { // ticket_alloc is the name of the repeater

        // get the old (saved) value
        $old_value = get_field('ticket_alloc', $post_id);

        // get the new (posted) value
        $new_value = $_POST['acf']['field_63ca95e88557a']; // this is the key of the repeater

        // check if the old value is the same as the new value
        if($old_value != $new_value) {
            // Do something if they are different
        } else {
            // Do something if they are the same
        }

    }

    // don't forget to return to be saved in the database
    return $value;

}
add_filter('acf/update_value', 'delegate_form_update', 10, 3);

Can anyone help, or point me in the right direction?

Thanks