How create new record with graphql?

I created a User schema with the Name string field. Using POST I can create a new record but not with graphql.

  const handleCreateUser = useCallback(() => {
    fetch('https://site-api.datocms.com/items',  {
      method: 'POST',
      headers: {
        Authorization: 'Bearer ...',
        Accept: 'application/json',
        'X-Api-Version': '3',
        'Content-Type': 'application/vnd.api+json'
      },
      body: JSON.stringify({
        data: {
          type: 'item',
          attributes: {
            name: '...',
          },
          relationships: {
            item_type: {
              data: {
                type: 'item_type',
                id: '...'
              }
            }
          }
        }
      }),
    })
    .then((res) => {
      console.log(res);
      return res.json();
    })
    .then((data) => {
      console.log(data);
    });
  }, []);

Thank you guys!

UPDATE: The GraphQL API is readonly on Dato, to create, edit or delete records, you can use our REST API instead: Overview — DatoCMS