ACF | Type: PHPACF Pro Site Options

For some reason, this HAS to be added to functions.php; MU plugin does not work.

if( function_exists('acf_add_options_page') ) {
    acf_add_options_page(array(
        'page_title' => 'Site Options',
        'menu_title' => 'Options',
        'menu_slug' => 'site-options',
        'capability' => 'edit_posts',
        'redirect' => false
    ));
    acf_add_options_sub_page(array(
        'page_title' 	=> 'Header Options',
        'menu_title'	=> 'Header',
        'parent_slug'	=> 'site-options',
    ));
    acf_add_options_sub_page(array(
        'page_title' 	=> 'Footer Options',
        'menu_title'	=> 'Footer',
        'parent_slug'	=> 'site-options',
    ));
}