custom.php

add_action('init', function () {
    $labels = [
        'name' => _x('Blog', 'post type general name'),
        'singular_name' => _x('Blog', 'post type singular name'),
        'add_new' => _x('Adicionar Novo', 'Novo item'),
        'add_new_item' => __('Novo Item'),
        'edit_item' => __('Editar Item'),
        'new_item' => __('Novo Item'),
        'view_item' => __('Ver Item'),
        'search_items' => __('Procurar Itens'),
        'not_found' =>  __('Nenhum registro encontrado'),
        'not_found_in_trash' => __('Nenhum registro encontrado na lixeira'),
        'parent_item_colon' => '',
        'menu_name' => 'Blog'
    ];

    $args = [
        'labels' => $labels,
        'public' => true,
        'public_queryable' => true,
        'show_ui' => true,
        'show_in_menu'  => true,
        'show_in_nav_menus'  => true,
        'show_in_admin_bar'  => true,
        'query_var' => true,
        'rewrite' => [
            'slug' => 'blog',
            'with_front' => false
        ],
        'capability_type' => 'post',
        'has_archive' => true,
        'hierarchical' => true,
        'menu_position' => 3,
        'register_meta_box_cb' => 'blog_meta_box',
        'supports' => [
            'title',
            'editor',
            'thumbnail',
            'comments',
            'excerpt',
            'revisions',
            'trackbacks'
        ],
        'taxonomies' => [
            'blog_category',
            'blog_tags'
        ]
    ];

    register_post_type('blog', $args);
    flush_rewrite_rules();
});

add_action('init', function () {
    $labels = [
        'name' => _x('Category', 'taxonomy general name'),
        'singular_name' => _x('Category', 'taxonomy singular name'),
        'search_items' =>  __('Search Category'),
        'all_items' => __('All Category'),
        'parent_item' => __('Parent Category'),
        'parent_item_colon' => __('Parent Category:'),
        'edit_item' => __('Edit Category'),
        'update_item' => __('Update Category'),
        'add_new_item' => __('Add New Category'),
        'new_item_name' => __('New Category Name'),
        'menu_name' => __('Category'),
    ];

    register_taxonomy('blog_category', ['blog'], [
        'hierarchical' => true,
        'labels' => $labels,
        'show_ui' => true,
        'show_admin_column' => true,
        'query_var' => true,
        'rewrite' => [
            'slug' => 'blog/categoria',
            'with_front' => false,
        ],
    ]);
    flush_rewrite_rules();
});

add_action('init', function () {
    $labels = [
        'name' => _x('Tag', 'taxonomy general name'),
        'singular_name' => _x('Tag', 'taxonomy singular name'),
        'search_items' =>  __('Search Tag'),
        'all_items' => __('All Tag'),
        'parent_item' => __('Parent Tag'),
        'parent_item_colon' => __('Parent Tag:'),
        'edit_item' => __('Edit Tag'),
        'update_item' => __('Update Tag'),
        'add_new_item' => __('Add New Tag'),
        'new_item_name' => __('New Tag Name'),
        'menu_name' => __('Tag'),
    ];

    register_taxonomy('blog_tag', ['blog'], [
        'hierarchical' => true,
        'labels' => $labels,
        'show_ui' => true,
        'show_admin_column' => true,
        'query_var' => true,
        'rewrite' => [
            'slug' => 'blog/tag',
            'with_front' => false
        ],
    ]);
    flush_rewrite_rules();
});