Graphql mutation with fetch

updateCountry_fetch.js

const updateCountryFetch = async (countryId, happinessFactor, population) => {
  const query = JSON.stringify({
    query: `mutation {
          updateCountry(
            id: "${countryId}"
            happinessFactor: ${happinessFactor}
            population: ${population}) { id }
        }
    `
  });

  const response = await fetch(graphCoolEndpoint, {
    headers: {'content-type': 'application/json'},
    method: 'POST',
    body: query,
  });
  
  const responseJson = await response.json();
  return responseJson.data;
};

thanks @phattranky