Getting and Error with Shopify Graphql cartCreate on the release candidate?

I’m trying to use Shopify Graphql to create a custom basket with cartCreate
Which is new and accessible on the 2020-10 endpoint:

https:// { shop } .myshopify.com/api/2020-10/graphql.json

This is my full code

import Cookies from "js-cookie";
import { GraphQLClient, gql } from "graphql-request";

async function shopifyRequest() {
  const graphQLClient = new GraphQLClient(
    "https://jamiegalbreath.myshopify.com/api/2020-10/graphql.json",
    {
      headers: {
        "Content-Type": "application/json",
        "X-Shopify-Storefront-Access-Token":
          process.env.REACT_APP_SHOPIFY_STOREFRONT_ACCESS_TOKEN,
      },
    }
  );


  const mutation = gql`
    mutation {
      cartCreate {
        cart {
          id
        }
        userErrors {
          code
          field
          message
        }
      }
    }
  `;

  const variables = {};

  const data = await graphQLClient.request(mutation, variables);

}

export async function test() {
  await shopifyRequest()
    .then(() => {
      console.log("DONE");
    })
    .catch((error) => console.error(error));
}

When the function returns I get an error:
Field ‘cartCreate’ doesn’t exist on type ‘Mutation’