Book category

if ( ! function_exists( 'syt_custom_book' ) ) {

// Register Custom Taxonomy
function syt_custom_book() {

	$labels = array(
		'name'                       => _x( 'Books', 'Taxonomy General Name', 'sytech' ),
		'singular_name'              => _x( 'Book', 'Taxonomy Singular Name', 'sytech' ),
		'menu_name'                  => __( 'Book', 'sytech' ),
		'all_items'                  => __( 'All Books', 'sytech' ),
		'parent_item'                => __( 'Parent Book', 'sytech' ),
		'parent_item_colon'          => __( 'Parent Book:', 'sytech' ),
		'new_item_name'              => __( 'New Book Name', 'sytech' ),
		'add_new_item'               => __( 'Add New Book', 'sytech' ),
		'edit_item'                  => __( 'Edit Book', 'sytech' ),
		'update_item'                => __( 'Update Book', 'sytech' ),
		'view_item'                  => __( 'View Book', 'sytech' ),
		'separate_items_with_commas' => __( 'Separate books with commas', 'sytech' ),
		'add_or_remove_items'        => __( 'Add or remove books', 'sytech' ),
		'choose_from_most_used'      => __( 'Choose from the most used', 'sytech' ),
		'popular_items'              => __( 'Popular Books', 'sytech' ),
		'search_items'               => __( 'Search Books', 'sytech' ),
		'not_found'                  => __( 'Not Found', 'sytech' ),
		'no_terms'                   => __( 'No Books', 'sytech' ),
		'items_list'                 => __( 'Books list', 'sytech' ),
		'items_list_navigation'      => __( 'Books list navigation', 'sytech' ),
	);
	$rewrite = array(
		'slug'                       => 'book',
		'with_front'                 => true,
		'hierarchical'               => true,
	);
	$args = array(
		'labels'                     => $labels,
		'hierarchical'               => true,
		'public'                     => true,
		'show_ui'                    => true,
		'show_admin_column'          => true,
		'show_in_nav_menus'          => true,
		'show_tagcloud'              => true,
		'rewrite'                    => $rewrite,
		'show_in_rest'               => true,
		'rest_base'                  => 'book',
	);
	register_taxonomy( 'book', array( 'book_page' ), $args );

}
add_action( 'init', 'syt_custom_book', 0 );

}