const SiteClient = require('datocms-client').SiteClient;
const client = new SiteClient('YOUR-API-TOKEN');
const itemTypeFilterId = '34';
client.itemTypeFilter.find(itemTypeFilterId)
.then((itemTypeFilter) => {
  console.log(itemTypeFilter);
})
.catch((error) => {
  console.error(error);
});

> node example.js
{
  "id": "34",
  "name": "Draft posts",
  "filter": {
    "status": {
      "eq": "draft"
    }
  },
  "shared": true,
  "itemType": "44"
}