Thank you very much eskimo.  By calling sendProviderMessage(_:responseHandler:) on the Container APP side, I was able to communicate with PacketTunnelProvider's handleAppMessage(_:completionHandler:). If possible, I would like to know how to communicate with PacketTunnelProvider without calling sendProviderMessage(_:responseHandler:) on the Container APP side. I want to tell the user what stage of the connection process they are currently in and the detailed reasons for any errors that occur. If we use the connection property of the NEVPNManager instance for this purpose, I would like to know how to change the NETunnelProviderManager.connection.status available in the Container APP from the PacketTunnelProvider side. And I would like to know how to add my own connection status. sincerely

The statement below was posted by mistake. My apologies. Thank you for your kind reply. When I made the changes as you suggested, I was able to use DispatchNotificationCenter. I had overlooked the Availability in the documentation. Thanks,