/**
 * Filter decision if post type is excluded from the XML sitemap.
 *
 * @param bool   $exclude Default false.
 * @param string $type    Post type name.
 */
add_filter( 'rank_math/sitemap/exclude_post_type', function( $exclude, $type ){
    if ( 'kc-section' === $type ) {
        return true;
    }

    return $exclude;
}, 10, 2 );