Why does setting the server response for a page in Bitrix not work?

Question

1C-Bitrix

In \bitrix\php_interface\init.php I registered

http_response_code(403);
exit;

but the response code is still 200.
This doesn't work either:

http_response_code(403);
echo http_response_code();
exit;

Answer 1

That's how it worked

header("HTTP/1.1 403");
exit;