BadMethodCallException on laravel authentication

I'm trying to make an authentication in laravel with multiple tables to separate user roles, is an academic exercise, so I can't do it any other way.

BadMethodCallException
Method App\Http\Controllers\Auth\RegisterController::create does not exist. 

This error comes up when I try to register a user in the database. I understand that this is when the redirection occurs.

So... these are my routes from web.php:

use Illuminate\Support\Facades\Route;
use App\Http\Controllers;


Route::get('/', function () {
    return view('welcome');
}); 

Auth::routes();

Route::get('/home', [App\Http\Controllers\HomeController::class, 'index'])->name('home');


Route::get('/login/admin', [App\Http\Controllers\Auth\LoginController::class,'showAdminLoginForm']);
Route::get('/login/user', [App\Http\Controllers\Auth\LoginController::class,'showUserLoginForm']); 
Route::get('/register/admin', [App\Http\Controllers\Auth\RegisterController::class,'showAdminRegisterForm']);
Route::get('/register/user', [App\Http\Controllers\Auth\RegisterController::class,'showUserRegisterForm']);

Route::post('/login/admin', [App\Http\Controllers\Auth\LoginController::class,'adminLogin']);
Route::post('/login/user', [App\Http\Controllers\Auth\LoginController::class,'userLogin']);
Route::post('/register/admin', [App\Http\Controllers\Auth\RegisterController::class,'createAdmin']);
Route::post('/register/user', [App\Http\Controllers\Auth\RegisterController::class,'createUser']);

Route::view('/home', 'home')->middleware('auth');
Route::view('/admin', 'admin');
Route::view('/user', 'user');

This is the RegisterController from App\Controllers\Auth\RegisterController:

<?php

namespace App\Http\Controllers\Auth;

use App\Http\Controllers\Controller;
use App\Providers\RouteServiceProvider;
use App\Models\User;
use App\Models\Admin;
use Illuminate\Foundation\Auth\RegistersUsers;
use Illuminate\Support\Facades\Hash;
use Illuminate\Support\Facades\Validator;
use Illuminate\Http\Request;

class RegisterController extends Controller
{

    use RegistersUsers;

    protected $redirectTo = RouteServiceProvider::HOME;

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

    protected function validator(array $data)
    {
        return Validator::make($data, [
            'name' => ['required', 'string', 'max:255'],
            'email' => ['required', 'string', 'email', 'max:255', 'unique:users'],
            'password' => ['required', 'string', 'min:8', 'confirmed'],
        ]);
    }

    //USER STUFF
    protected function createUser(Request $request)
    {
        $this->validator($request->all())->validate();
        $user = User::create([
            'username' => $request['username'],
            'name' => $request['name'],
            'email' => $request['email'],
            'password' => Hash::make($request['password']),
        ]);
        return redirect()->intended('login/user');
    }

    public function showUserRegisterForm()
    {
        return view('auth.register', ['url' => 'user']);
    }

    //ADMIN STUFF
    protected function createAdmin(Request $request)
    {
        $this->validator($request->all())->validate();
        $admin = Admin::create([
            'username' => $request['username'],
            'name' => $request['name'],
            'email' => $request['email'],
            'password' => Hash::make($request['password']),
        ]);
        return redirect()->intended('login/admin');
    }

    public function showAdminRegisterForm()
    {
        return view('auth.register', ['url' => 'admin']);
    }

}

Also I think that this is necessary, the auth.php file, where guards are defined:

    'defaults' => [
        'guard' => 'web',
        'passwords' => 'users',
    ],


    'guards' => [
        'web' => [
            'driver' => 'session',
            'provider' => 'users',
        ],

        'api' => [
            'driver' => 'token',
            'provider' => 'users',
            'hash' => false,
        ],
        'admin' => [
            'driver' => 'session',
            'provider' => 'admins',
            'hash' => false,
        ],
        'user' => [
            'driver' => 'session',
            'provider' => 'users',
            'hash' => false,
        ],
        
    ],



    'providers' => [
        'users' => [
            'driver' => 'eloquent',
            'model' => App\Models\User::class,
        ],

        'admins' => [
            'driver' => 'eloquent',
            'model' => App\Models\Admin::class,
        ],

        // 'users' => [
        //     'driver' => 'database',
        //     'table' => 'users',
        // ],
    ],

Models for user and admin:

User:

namespace App\Models;

use Illuminate\Contracts\Auth\MustVerifyEmail;
use Illuminate\Database\Eloquent\Factories\HasFactory;
use Illuminate\Foundation\Auth\User as Authenticatable;
use Illuminate\Notifications\Notifiable;

class User extends Authenticatable
{
    use HasFactory, Notifiable;

    protected $guard = 'user';
    protected $fillable = [
        'username',
        'name',
        'email',
        'password',
    ];

    protected $hidden = [
        'password',
        'remember_token',
    ];

    protected $casts = [
        'email_verified_at' => 'datetime',
    ];
}

Admin:

<?php

namespace App\Models;

use Illuminate\Contracts\Auth\MustVerifyEmail;
use Illuminate\Database\Eloquent\Factories\HasFactory;
use Illuminate\Foundation\Auth\User as Authenticatable;
use Illuminate\Notifications\Notifiable;

class User extends Authenticatable
{
    use HasFactory, Notifiable;
    
    protected $guard = 'admin';
    protected $fillable = [
        'username',
        'name',
        'email',
        'password',
    ];

    protected $hidden = [
        'password',
        'remember_token',
    ];

    protected $casts = [
        'email_verified_at' => 'datetime',
    ];
}

I'm not sure if I forgot something, but I've been stuck in the same error for several hours and I can't see what I'm doing wrong... In any case I will edit this with the necessary information if I have forgotten something.

In case it is necessary and to provide more information that I think is important, I'll add the link to the tutorial that I've been following, if someone knows how to fix it, or finds the bug. https://pusher.com/tutorials/multiple-authentication-guards-laravel