gistfile1.txt

add_filter( 'propertyhive_microsoft_graph_event_negotiator_ids', 'only_certain_members', 10, 2 );
function only_certain_members( $attending_wordpress_user_ids, $post_id )
{
    if ( empty($attending_wordpress_user_ids) )
    {
        $attending_wordpress_user_ids = array(1, 2, 3, 4); // CHANGE THIS!!
    }
    
    return $attending_wordpress_user_ids;
}