currently I am using the Shopify GraphiQL App to explore & play around with the Storefront API. When I am trying to authenticate a User with the customerAccessTokenCreate method, I get the following error message:
Field 'customerAccessTokenCreate' doesn't exist on type 'Mutation'
I have also noticed, that the Docs tab at the right of the App doesn't contain this method as well - however it's described in the official Shopify API documentation: https://help.shopify.com/en/api/storefront-api/reference/mutation/customeraccesstokencreate
Sorry if this is too late but I have been playing around with the API's since the new year
What you will need to is to use a graphql client link insomnia or postman.
Then follow this guide....
Hope this helps!