import { buildClient } from '@datocms/cma-client-node';
async function run() {
  const client = buildClient({ apiToken: '<YOUR_API_TOKEN>' });
  
  const modelIdOrApiKey = 'blog_post';
  
  const itemType = await client.itemTypes.duplicate(modelIdOrApiKey);
  
  console.log(itemType);
}
run();

{
  id: '44',
  name: 'Blog post',
  api_key: 'post',
  collection_appearance: 'compact',
  singleton: false,
  all_locales_required: false,
  sortable: true,
  modular_block: false,
  draft_mode_active: false,
  tree: false,
  ordering_direction: null,
  ordering_meta: 'created_at',
  hint: 'Blog posts will be shown in our website under the Blog section',
  inverse_relationships_enabled: false,
  meta: {
    has_singleton_item: false
  },
  singleton_item: null,
  fields: [
    {
      type: 'field',
      id: '124'
    }
  ],
  fieldsets: [
    {
      type: 'fieldset',
      id: '124'
    }
  ],
  title_field: null,
  image_preview_field: null,
  excerpt_field: null,
  ordering_field: null,
  workflow: null
}