Does it possible to work with graph.cool from file:/// protocol? If I set no-cors, fetch automatically sets Content-Type: text/plain to request header and I receive 415, with cors I receiving 405 https://developer.mozilla.org/en-US/docs/Web/HTTP/CORS#Simple_requests

The only allowed values for the Content-Type header are:
application/x-www-form-urlencoded
multipart/form-data
text/plain