Angular 6: Custom Header 'Authorisation' not working Angular 6

I am new to Angular 6, and I am having one issue with custom header for Authorisation. I am setting a Oauth2 token in Authorisation header but it is not going along with request. I have done a lot of googling but none of the solution solves my problem. Below I am adding code.

Custom header in request:

getCurrentUser() {
    let token = this.cookie.get('token');
    return this.http.get<User[]>(serverurl + 'getUser',{
        headers: new HttpHeaders().set('Authorization', token),
    }) // this.httpOptions
      .pipe(
      tap(user => this.log(`fetched current user`)),
      catchError(this.handleError('currentUser', []))
      );
  }

As request Interceptor:

import { AuthService } from '../services/auth.service';
import { Injectable } from '@angular/core';
import { HttpEvent, HttpInterceptor, HttpHandler, HttpRequest, HttpHeaders } from '@angular/common/http';
import { Observable } from 'rxjs';
import { CookieService } from 'ngx-cookie-service';

@Injectable()
export class AuthInterceptor implements HttpInterceptor {

    constructor(private auth: AuthService, private cookie: CookieService) { }

    intercept(req: HttpRequest<any>, next: HttpHandler) {
        let token = this.cookie.get('token');
        let changedRequest = req;
        // HttpHeader object immutable - copy values
        const headerSettings: { [name: string]: string | string[]; } = {};

        if (token) {
            headerSettings['Authorization'] = 'Bearer ' + token;
        }
        // headerSettings['Content-Type'] = 'application/json';
        const newHeader = new HttpHeaders(headerSettings);
        changedRequest = req.clone({
            headers: newHeader
        });
        return next.handle(changedRequest);
    }
}

It gives following request:

Authorisation token is added in Access-control-request-Header instead of Authorisation itself. And I don't see Authorisation header in request.

Thanks in Advance...!

After searching a lot for this I found the solution for this:

There is no problem in the code, since you are using Cross Origin request it first sent OPTIONS request to the server. In order to fix this I added following piece of code in my server configuration section:

.antMatchers(HttpMethod.OPTIONS, "/**").permitAll()

It has nothing to do with Angular 6. Basically you need to Allow OPTIONS method for all URLs from server side. And it will work. :)