Replacement for show_error-function from CI3

Hi,

i use show_error($message, 403, 'forbidden'); in CI3. What is the replacement for this function in CI4?

Code:

$response->setStatusCode(403)
                    ->setBody('You do not have access to this page');

Code:

$response->setStatusCode(403)
                    ->setBody('You do not have access to this page');

Thank you.