OPTIONS preflight error in Chrome

[emmanuelrflores]

When trying to make a basic call, I will get a preflight error

Failed to load https://myinstance.testrail.com/index.php?/api/v2/get_project/1: Response to preflight request doesn't pass access control check: No 'Access-Control-Allow-Origin' header is present on the requested resource. Origin 'http://localhost:3000' is therefore not allowed access. The response had HTTP status code 400. If an opaque response serves your needs, set the request's mode to 'no-cors' to fetch the resource with CORS disabled.

Is there a way to set that? Or is there some other special setting I need to do?