How to list categories and subcategories from wp_term_taxonomy table?

Question

MySQL

how to display a list of categories and subcategories from the wp_term_taxonomy table if I have a multisite - I need to take it from the second site and display it in the first one for the sitemap. database is one.
tried various functions but nothing comes out.
wp_get_object_terms('3', 'ru_cat'); what am I doing wrong?
the whole output code is like this:

<?php $blogs = get_last_updated();
foreach ($blogs AS $blog) {
  switch_to_blog($blog["blog_id"]); bloginfo('name');

wp_get_object_terms('', 'ru_cat');

wp_list_pages('exclude=2,5');
restore_current_blog();
} ?>