CI4 equivalent of $this->form_validation->set_data($data);

Hello,

I need to validate a value outside of $_POST data. In CI3 I could easily manually assign data before running validation:

PHP Code:

$data = array(
        'username' => 'johndoe',
        'password' => 'mypassword',
        'passconf' => 'mypassword'
);

$this->form_validation->set_data($data); 


But it seems this feature is not exist on CI4.

How to do this?

Thanks.