title: Request header field Content-Type is not allowed by Access-Control-Allow-Headers in flight response
body: <p>I am developing an Angular 4 application with Laravel (Restful API). I have tested the API with Postman. It's working fine but when I call the API from Angular 4 I am getting this error:</p>
  
  <p><a href="https://i.stack.imgur.com/brybR.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/brybR.jpg" alt="enter image description here"></a></p>
  
  <pre><code>import { Injectable } from '@angular/core';
  import { Headers, Http } from '@angular/http';
  import { User } from '../models/user';
  import 'rxjs/add/operator/toPromise';
  
  @Injectable()
  export class AuthService {
   private BASE_URL: string = 'http://localhost/fmfb_hr/public/api';
    private headers: Headers = new Headers({'Content-Type': 'application/json'});
   constructor(private http: Http) {}
  login(user): Promise&lt;any&gt; {
  let url: string = `${this.BASE_URL}/login`;
  return this.http.post(url, user, {headers: this.headers}).toPromise();
  }
  
  
  }
  </code></pre>