Exclude Children Post

$args = [
        'post_type'      => 'post',
        'post_status'    => 'publish',
        'posts_per_page' => $post_number + 1,
        'paged'          => ( get_query_var( 'paged' ) ) ? get_query_var( 'paged' ) : 1,
        'tax_query'      => [
            [
                'taxonomy'         => $taxonomy,
                'field'            => 'term_id',
                'terms'            => $category_id,
                'include_children' => false
            ],
        ],
    ];