Backbone Fetch Request是OPTIONS方法

I have a Backbone Collection object with the following URL "https://localhost:8080/api/menu/1/featured". I am trying to perform a fetch operation to retrieve the collection from the url and parse it. However, on the server side, the method type that I see for this request is OPTIONS. The server is only suppose to support GET method. I am not sure how Backbone is figuring out what method type to use, and why it changes to OPTIONS method type randomly sometimes. I am using a Node.js server to process the request. This code below is pretty much what I did.I have a Backbone Collection object with the fo