validation error

I encountered a confusing validation error,
so i try validation in model but i confusing about the error this is the error

my model validation : 

PHP Code:

<?php

namespace App\Models;

use CodeIgniter\Model;

class AdministratorModel extends Model
{
protected $DBGroup          = 'default';
protected $table            = 'administrators';
protected $primaryKey      = 'id';
protected $useAutoIncrement = true;
protected $insertID        = 0;
protected $returnType      = 'array';
protected $useSoftDeletes  = true;
protected $protectFields    = true;
protected $allowedFields    = [
'full_name','username','email',
'password'
];

// Validation
protected $validationRules = [
'full_name'    => ['label' => 'Full name', 'rules' => 'required|alpha_numeric_space'],
'username'    => ['label' => 'Username', 'rules' => 'required|alpha_numeric|min_length[2]|is_unique[administrators.username]'],
'email'        => ['label' => 'Email', 'rules' => 'required|valid_email|is_unique[administrators.email]'],
'password'    => ['label' => 'Password', 'rules' => 'required|min_length[6]'],
'pass_con' => ['label' => 'Password Confirmation', 'rules' => 'required'],
];
protected $validationMessages  = [];
protected $skipValidation      = false;
protected $cleanValidationRules = true;

public function _values()
{
return [
'full_name' => _post('full_name'),
'username' => _post('username'),
'email' => _post('email'),
'password' => _post('password')
];
}

public function store()
{
$req = $this->_values();
$this->insert($req);
}

} 


my controller method

PHP Code:

    /**
     * Create a new resource object, from "posted" parameters
     *
     * @return mixed
     */
    public function create()
    {
        $ins = $this->model->store();
        $validation = $this->model->errors();

        echo '<h1>incoming request :</h1> <br>';
        echo '<pre>';
        print_r(_post());
        echo '</pre>';
        if ($validation) {
            echo '<h1>validation error :</h1> <br>';
            echo '<pre>';
            print_r($validation);
            echo '</pre>';
        } else {
            echo $this->model->getInsertID();
        }
    } 


my view :

Code:

<?= form_open(route_to('administrator_create')); ?>
          <div class="form-group">
            <label for="full_name">Full name</label>
            <input type="text" class="form-control full_name" name="full_name" id="full_name" placeholder="Full name">
          </div>

          <div class="form-group">
            <label for="username">Username</label>
            <input type="text" class="form-control username" name="username" id="username" placeholder="Username" >
          </div>

          <div class="form-group">
            <label for="email">Email</label>
            <input type="email" class="form-control email" name="email" id="email" placeholder="Email" >
          </div>

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

          <div class="form-group">
            <label for="pass_con">Re-type Password</label>
            <input type="password" class="form-control pass_con" name="pass_con" id="pass_con" placeholder="Re-type Password">
          </div>

          <button type="submit" class="btn btn-primary px-5">Submit</button>
        <?= form_close() ?>

you don't pass pass_con in _values() method.

you don't pass pass_con in _values() method.

ahh,, i miss it thank you