Laravel Multi-Auth Routing issue

When i install multi-auth in laravel but routing issue occur.

I'm edit in web.php when address bar write in ,

localhost/projectname/admin

but error occur - page not found but i passed specific address like this

localhost/projectname/admin/login

after that page open BUT this not good. can you possible i'm only pass

localhost/projectname/admin 

after that page(view) open ?

my routes

Route::get('/admin', 'AdminController@index');

Controller file AdminController

<?php

namespace App\Http\Controllers;

use Illuminate\Http\Request;

class HomeController extends Controller
{
    /**
     * Create a new controller instance.
     *
     * @return void
     */

    public function __construct()
    {
        $this->middleware('auth:admin');
    }

    /**
     * Show the application dashboard.
     *
     * @return \Illuminate\Http\Response
     */
    public function index()
    {
        return view('admin');
    }
}

via Chebli Mohamed