protect page in agnular when user didn't login

import { Injectable } from '@angular/core';

import { CanActivate, Router } from '@angular/router';

@Injectable({

 providedIn: 'root'

})

export class AuthGuard implements CanActivate {

 constructor(private router: Router) {}

 canActivate(): boolean {

  if (!this.isAuthenticated()) {

   this.router.navigate(['/login']);

   return false;

  }

  return true;

 }

 isAuthenticated(): boolean {

  // Check if the user is authenticated, 

  // for example by checking local storage or a session cookie.

  return !!localStorage.getItem('token');

 }

}