How to Hide Custom Alert Manager Admin Menus

function plt_hide_custom_alert_manager_menus() {
	//Hide "Custom Alert Manager".
	remove_menu_page('cam-category-list');
	//Hide "Custom Alert Manager → Categories".
	remove_submenu_page('cam-category-list', 'cam-category-list');
	//Hide "Custom Alert Manager → All Alerts".
	remove_submenu_page('cam-category-list', 'alert-list');
	//Hide "Custom Alert Manager → Add New".
	remove_submenu_page('cam-category-list', 'alert-insert');
}

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

Where do I put this code?