fetchGraphQL function that handles sending queries to the API:

const fetchGraphQL = (query, variables = {}) => {
  return fetch("https://countries.trevorblades.com/", {
    method: "POST",
    headers: { "Content-Type": "application/json" },
    body: JSON.stringify({
      query,
      variables,
    }),
  }).then((res) => res.json());
};