Implement Authentication in Angular App

app.service.ts

import { Injectable } from '@angular/core';
import { HttpClient, HttpHeaders } from '@angular/common/http';
import { map } from 'rxjs/operators';

@Injectable()
export class AppService {

  constructor(private http: HttpClient) { }

  getCountries() {
    const headers = new HttpHeaders();
    headers.append('Authorization', `Bearer ${token}`);
    return this.http.get('/api/country', { headers });
  }
}

auth.interceptor.ts

import { Injectable } from '@angular/core';
import { HttpClient, HttpHeaders } from '@angular/common/http';
import { map } from 'rxjs/operators';

@Injectable()
export class AuthInterceptorService {

  constructor(private http: HttpClient) { }

  getCountries() {
    const headers = new HttpHeaders();
    headers.append('Authorization', `Bearer ${token}`);
    return this.http.get('/api/country', { headers });
  }
}