not found message for wordpress custom taxonomy - wordpress

Question

i created a custom taxonomy named cancers and a template file for this taxonomy named taxonomy-cancers.php but when i call this url:
http://localhost/cancers even http://localhost/?tax=cancers
wordpress shows page not found and doesn't use my taxonomy template.
this is my code for defining custom taxonomy:
add_action( 'init', 'create_cancers_taxonomy', 0 );
function create_cancers_taxonomy() {
// Add new taxonomy, make it hierarchical (like categories)
$labels = array(
'name' => _x( 'سرطان‌ها', 'taxonomy general name' ),
'singular_name' => _x( 'سرطان', 'taxonomy singular name' ),
'search_items' => __( 'جستجو در میان سرطان‌ها' ),
'all_items' => __( 'تمامی سرطان‌ها' ),
'parent_item' => __( 'دسته اصلی' ),
'parent_item_colon' => __( 'دسته اصلی:' ),
'edit_item' => __( 'ویرایش سرطان' ),
'update_item' => __( 'بروزرسانی سرطان' ),
'add_new_item' => __( 'افزودن سرطان' ),
'new_item_name' => __( 'عنوان سرطان' ),
'menu_name' => __( 'سرطان‌ها' ),
);
$args = array(
'hierarchical' => true,
'labels' => $labels,
'show_ui' => true,
'show_admin_column' => true,
'query_var' => true,
);
register_taxonomy( 'cancers', array('cancer', 'post'), $args );
}

Answer 1

I think you forgot to add rewrite parameter in arguments,
Use this arguments:--
$args = array(
'hierarchical' => true,
'labels' => $labels,
'show_ui' => true,
'show_admin_column' => true,
'query_var' => true,
'rewrite' => array( 'slug' => 'cancers' ),
);
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