The POST method is not supported for this route. Supported methods: GET, HEAD. When I want to save a form data with modal

basically i want to save the data from a modal form to databases.

the modal that i use is modal from a bootstrap i place it at main.blade.php and i create a AuthControler with artisan without -r. and add a new routes into web.php if you ask why i didnt use php artisan make:auth. well it's because its more complicated to edit the whole code to my own html code that i already made it from the first time IMO. hope you all can help me.

here is the main layout

main.blade.php

    
        <div id="modal-register" class="modal fade">
            <div class="modal-dialog modal-register">
                <div class="modal-content">
                    <form method="post" action="">
                        <div class="modal-header">
                            @csrf
                            <h4 class="modal-title">Register</h4>
                            <button type="button" class="close" data-dismiss="modal" aria-hidden="true">&times;</button>
                        </div>
                        <div class="modal-body">
                            <div class="form-group">
                                <label>Nama Lengkap</label>
                                <input type="text" name="name" id="input-name"class="form-control" required="required">
                            </div>
                            <div class="form-group">

                                <label>Email</label>
                                <input type="email" name="email" id="input-email" class="form-control" required="required" placeholder="ex:abcdefg@gmail.com">
                            </div>

                            <div class="form-group">
                                <div class="clearfix">
                                    <label>Password</label>
                                    <input type="password" name="password" id="input-password" class="form-control" required="required">
                                </div>
                            </div>

                            <div class="form-group">
                                <div class="clearfix">
                                    <label>Konfirmasi Password</label>
                                    <input type="password" name="password-confirmation" id="input-password" class="form-control" required="required" placeholder="Masukkan kembali password anda">
                                </div>
                            </div>

                        </div>
                        <div class="modal-footer">
                            <input type="submit" class="btn btn-primary pull-right service-btn" value="Register">
                        </div>
                    </form>
                </div>
            </div>
        </div>
    

AuthController.php

<?php

namespace App\Http\Controllers;

use Illuminate\Http\Request;

class AuthController extends Controller
{
    //
    public function getLogin(){
        return view('login');
    }

    public function postLogin(Request $request){
        //
    }

    public function getRegister(){
        return view('Register');
    }


    public function postRegister(Request $request){
        dd('ok');
    }


}

web.php

<?php

//register
route::get('/register','AuthController@getRegister');
route::post('/register','AuthController@postRegister');

//login
route::get('/login','AuthController@getLogin');
route::post('/login','AuthController@postLogin');