How to Hide the "Freelancehunt reviews" Admin Menu

function plt_hide_reviews_for_freelancehunt_menus() {
	//Hide the "Settings → Freelancehunt reviews" menu.
	remove_submenu_page('options-general.php', 'freelancehunt_slug');
}

add_action('admin_menu', 'plt_hide_reviews_for_freelancehunt_menus', 11);

Where do I put this code?