按照教程做到 6.2 显示用户信息，为什么输入 URL 后报这样的错误？

错误截图，URL见红箭头处

user控制器代码：

<?php

namespace App\Http\Controllers;

use Illuminate\Http\Request;
use App\Models\User;

class UsersController extends Controller
{
    public function create()
    {
        return view('users.create');
    }

    public function show(User $user)
    {
        return view('users.show', compact('user'));
    }
}

user模型代码

<?php

namespace App\Models;

use Illuminate\Notifications\Notifiable;
use Illuminate\Contracts\Auth\MustVerifyEmail;
use Illuminate\Foundation\Auth\User as Authenticatable;

class User extends Authenticatable
{
    use Notifiable;
    protected $table = 'users';
    /**
     * The attributes that are mass assignable.
     *
     * @var array
     */
    protected $fillable = [
        'name', 'email', 'password',
    ];

    /**
     * The attributes that should be hidden for arrays.
     *
     * @var array
     */
    protected $hidden = [
        'password', 'remember_token',
    ];

    /**
     * The attributes that should be cast to native types.
     *
     * @var array
     */
    protected $casts = [
        'email_verified_at' => 'datetime',
    ];
}

路由代码

<?php
Route::get('/', 'StaticPagesController@home')->name('home');
Route::get('/help', 'StaticPagesController@help')->name('help');
Route::get('/about', 'StaticPagesController@about')->name('about');

Route::get('signup', 'UsersController@create')->name('signup');
Route::resource('users', 'UsersController');

请大佬指教！