How to Hide Animatikon - Scroll Animations & Motion Effects Admin Menus

function plt_hide_animatikon_scroll_animations_motion_effects_menus() {
	//Hide the "Settings → Animatikon" menu.
	remove_submenu_page('options-general.php', 'animatikon-settings');
	//Hide the "Settings → Contact Us" menu.
	remove_submenu_page('options-general.php', 'animatikon-settings-contact');
	//Hide the "Settings → Upgrade" menu.
	remove_submenu_page('options-general.php', 'animatikon-settings-pricing');
}

add_action('admin_menu', 'plt_hide_animatikon_scroll_animations_motion_effects_menus', 1000000000);

Where do I put this code?