How to Hide Viber Chat Support Admin Menus

function plt_hide_chat_viber_menus() {
	//Hide the "Viber Chat" menu.
	remove_menu_page('vchat');
	//Hide the "Viber Chat → Viber Chat" menu.
	remove_submenu_page('vchat', 'vchat');
	//Hide the "Viber Chat → 👑 Upgrade to Pro!" menu.
	remove_submenu_page('vchat', 'https://1.envato.market/YgJ10O');
}

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

Where do I put this code?