How to make the script work on all pages except the main one?

Question

WordPress

There is a self-written php script in the header.php file in the theme editor. How can I make it work on ALL pages except the home page? Can some parameter be checked by a condition?

Answer 1

https://w1c.ru/php-37.html
In the condition you check by negation if (the page is not the main one) {body}

Answer 2

Can some parameter be checked by a condition?

Exactly, that's what is needed. Apply conditional logic.
if( !is_home() || !()is_front_page() )
Reading - https://codex.wordpress.org/Conditional_Tags