Example
// Website you wish to allow to connect to
response.setHeader('Access-Control-Allow-Origin', '*');
// Request methods you wish to allow
response.setHeader('Access-Control-Allow-Methods', 'GET, POST, OPTIONS, PUT, PATCH, DELETE');
// Request headers you wish to allow
response.setHeader('Access-Control-Allow-Headers', 'X-Requested-With,content-type');
// Set to true if you need the website to include cookies in the requests sent
// to the API (e.g. in case you use sessions)
response.setHeader('Access-Control-Allow-Credentials', true);