Call to undefined method Config\Encryption::creatKey()

I read the documentation as wrote my exactly based on the doc.

PHP Code:

    $encrypter = \Config\Services::encrypter();
     $key = Encryption::creatKey(32); //Class 'App\Controllers\Encryption' not found
     $key = \Config\Encryption::creatKey(32); //Call to undefined method Config\Encryption::creatKey() 


$key = \CodeIgniter\Encryption\Encryption::createKey(32);

$key = \CodeIgniter\Encryption\Encryption::createKey(32);

Yes. it works, thanks.