CORS header ‘Access-Control-Allow-Origin’ missing - CORS request did not succeed

I am facing issue calling Remote API from localhost.

I am using nimble:restivus package

As per documentation I am setting:

enableCors: true

in order to allow access from any origin. But no luck.

This is the error I am getting in browser console:

Cross-Origin Request Blocked: The Same Origin Policy disallows reading 
the remote resource at http://192.168.18.20:9000/api/getUsers. 
(Reason: CORS header ‘Access-Control-Allow-Origin’ missing).

Here is my server side code:

myApi = new Restivus({
    
    apiPath: 'api/',
    enableCors: true,
    useDefaultAuth: false,
    prettyJson: true,
    defaultOptionsEndpoint: {
        action: function() {
            this.response.writeHead(201, {
                "Access-Control-Allow-Origin", "*",
                "Access-Control-Allow-Headers", "Origin, X-Requested-With, Content-Type, Accept, Z-Key, Authorization"
                "Content-Type": "application/json",
                "Access-Control-Allow-Methods": "GET, POST, PUT, DELETE, OPTIONS"
            });
            this.done();
            return {
                status: "success",
                "data": {
                    "message": "We love OPTIONS"
                }
            };
        }
    }
});

Here is my client side code:

$.ajax
        ({
          type: "POST",
          url: "https://example.com/api/getUsers",
          dataType: 'json',
          headers: {
            "Authorization": "Bearer eyJhbGciOiJIUzI1NiIsInR5