create.php

<!--list errors, formatted-->

<?= validation_list_errors() ?>

<!--errors array-->

<?php $errors = validation_errors(); var_dump($errors); ?>

<!--check if errors not empty, and list it-->

<?php if (!empty(validation_errors())) : ?>
<div class="alert alert-danger" role="alert">
  <?= validation_list_errors() ?>
</div>
<?php endif ?>

<!--show single error-->

<?= validation_show_error('description') ?>

TestController.php

    public function store()
    {
        $rules = [
            'title' => 'required',
            'description' => 'required',
        ];

        if (! $this->validate($rules)) {
            return redirect()->back()->withInput();
        }
        
        $data = [
            'title' => $this->request->getPost('title'),
            'description' => $this->request->getPost('description'),
        ];

        $department_model = new Department();

        $department = $department_model->insert($data);

        session()->setFlashdata('success', 'Department created');

        return redirect()->to('/departments');
    }