I was able to fetch data by following the Node and React tutorial https://developers.shopify.com/tutorials/build-a-shopify-app-with-node-and-react/fetch-data-with-apo.... Everything worked good, but after I logged out from the test store and logged in, I only get an error page: Network error: Unexpected token < in JSON at position 0. I googled it, it's an error that Shopify try to parse an html page, which is an 404 Not Found page.
I try to dig it up, and found out that the GraphQL query with the access token was sent to https://my-app-domain.com/graphql, my server with koa-shopify-graphql-proxy received the request at /graphql, but it try to get https://my-app-domain.com/admin/auth/login, which result in a 404 request.
I updated the packages to latest, restart my server, browser, and reinstall the app, but still no luck.
Any help would be appreciated, thank you.