cors

[dajuguan]

I have implemented the code in misson-3, however the following issue happens when loading the http://localhost:3000/dappies page.
Access to fetch at 'https://access-testnet.onflow.org/v1/scripts?block_height=sealed' from origin 'http://localhost:3000' has been blocked by CORS policy: No 'Access-Control-Allow-Origin' header is present on the requested resource. If an opaque response serves your needs, set the request's mode to 'no-cors' to fetch the resource with CORS disabled. http-request.js:102 POST https://access-testnet.onflow.org/v1/scripts?block_height=sealed net::ERR_FAILED 404