How to Hide TheBooking Admin Menus

function plt_hide_thebooking_menus() {
	//Hide "TheBooking".
	remove_menu_page('thebooking');
	//Hide "TheBooking → Reservations".
	remove_submenu_page('thebooking', 'thebooking');
	//Hide "TheBooking → Services".
	remove_submenu_page('thebooking', 'thebooking-services');
	//Hide "TheBooking → Customers".
	remove_submenu_page('thebooking', 'thebooking-customers');
	//Hide "TheBooking → Availability".
	remove_submenu_page('thebooking', 'thebooking-availability');
	//Hide "TheBooking → Core settings".
	remove_submenu_page('thebooking', 'thebooking-core');
}

add_action('admin_menu', 'plt_hide_thebooking_menus', 11);
Where do I put this code?