codeigniter 4 redirect back code example

Example 1: redirect back in codeigniter

This should help :
http://www.codeigniter.com/user_guide/libraries/user_agent.html

$this->load->library('user_agent');
if ($this->agent->is_referral()){
    echo $this->agent->referrer();
}

or straight PHP:

redirect($_SERVER['HTTP_REFERER']);

Example 2: codeigniter 4 redirect to home

return redirect()->to(site_url());