Ionic3 push notification


I have an ionic chat application built with sockets, nodejs, and MongoDB. I want to send a push notification when a user receives a new message if they do not have the app open. I have successfully created push’s with ionic push in ionic1, but now I am running ionic 3. Since firebase is not my backend, I don’t plan to use it at all. Any suggestions on how I can acocmplish this task?