Error validation does not appear CodeIgniter 4

Question

I have a problem with the validation error for CodeIgniter 4, when i click the button, the error message doesn't appear at all, is there something wrong? Please help, I appreciate it Below is the code:

Controller

public function Daftar()
    {
        // Jika tervalidasi
        if ($this->validate([
            'nim' => [
                'label' => 'NIM',
                'rules' => 'required|is_unique[tbl_anggota.nim]',
                'errors' => [
                    'required' => '{field} Masih Kosong!',
                    'is_unique' => '{field} NIM Sudah Terdaftar!',
                ]
            ],
            'nama' => [
                'label' => 'Nama',
                'rules' => 'required',
                'errors' => [
                    'required' => '{field} Masih Kosong!',
                ]
            ],
            'password' => [
                'label' => 'Password',
                'rules' => 'required',
                'errors' => [
                    'required' => '{field} Masih Kosong!',
                ]
            ],
            'ulangi_password' => [
                'label' => 'Ulangi Password',
                'rules' => 'required|matches[password]',
                'errors' => [
                    'required' => '{field} Masih Kosong!',
                    'matches' => '{field} Password Tidak Sama!',
                ]
            ],
        ])) {
        }  else {
             // Jika tidak tervalidasi
            session()->getFlashdata('errors', \Config\Services::validation()->getErrors());
            return redirect()->to(base_url('Auth/Login'))->withInput('validation', \Config\Services::validation());
        }
    }

View

<?php
            // Notifikasi Error
            $errors = session()->getFlashdata('errors');
            if (!empty($errors)) { ?>
                <div class="alert alert-danger" role="alert">
                    <h4>Periksa Entry Form</h4>
                    <ul>
                        <?php foreach ($errors as $key => $error) { ?>
                            <li><?= esc($error) ?></li>
                        <?php } ?>
                    </ul>
                </div>
            <?php } ?>

Thank you so much!!

I've tried look it up but still it's not working

Answer 1

you need to use setFlashData() instead of getFlashData() while setting error in your controller, so change:

..
session()->getFlashdata('errors', \Config\Services::validation()->getErrors());
..

to

..
session()->setFlashdata('errors', \Config\Services::validation()->getErrors());
..