PHP Mail does not add X-PHP-Script

I installed Ubuntu 22.04, php 8.1.2, Apache 2.4.52 and postfix. When I run test.php in browser with the code

mail($to, $subject, $body)

I receive the email without X-PHP-Script header. I expect to see

X-PHP-Script: <server_name><php_self> for <remote-addr>

After I set

mail.add_x_header = On

the header X-PHP-Originating-Script was added to a mail, but not X-PHP-Script. If I am not wrong, PHP mail always added X-PHP-Script. I can add it manually via additional_headers parameter of mail function, but how to make PHP mail add it?