1. 确认后端API是否正确返回了Authorization头信息，若未返回则需修改API代码，添加Authorization头信息。

2. 在Angular中配置请求拦截器，在每个HTTP请求中添加Authorization头信息。示例代码如下：

@Injectable()
export class AuthInterceptor implements HttpInterceptor {

  constructor(private authService: AuthService) { }

  intercept(req: HttpRequest, next: HttpHandler): Observable> {
    const authToken = this.authService.getAuthorizationToken();
    const authReq = req.clone({ setHeaders: { Authorization: authToken } });
    return next.handle(authReq);
  }
}

@NgModule({
  declarations: [...],
  imports: [...],
  providers: [
    AuthService,
    {
      provide: HTTP_INTERCEPTORS,
      useClass: AuthInterceptor,
      multi: true
    }
  ],
  bootstrap: [AppComponent]
})
export class AppModule { }

其中，getAuthorizationToken()方法为获取本地存储中的Authorization Token。

3. 手动添加Authorization头信息。示例代码如下：

import { HttpClient, HttpHeaders } from '@angular/common/http';

@Injectable()
export class ApiService {
  private apiUrl = 'http://example.com/api/';

  constructor(private http: HttpClient) { }

  getData() {
    const httpOptions = {
      headers: new HttpHeaders({
        'Content-Type': 'application/json',
        'Authorization': 'Bearer ' + localStorage.getItem('auth_token')
      })
    };
    return this.http.get(this.apiUrl + 'data', httpOptions);
  }
}

其中，'Bearer '为Authorization类型，localStorage.getItem('auth_token')获取本地存储中的Authorization Token。