How to Hide the "LLMS Full TXT Generator" Admin Menu

function plt_hide_llms_full_txt_generator_menus() {
	//Hide the "Settings → LLMS Full TXT Generator" menu.
	remove_submenu_page('options-general.php', 'llms-full-txt-generator');
}

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

Where do I put this code?