Can there be a push strategy for apps that use personal servers?


I have written a home security monitor application that works with the popular open source ZoneMinder CCTV surveillance software. ZoneMinder is a software suite that gets installed on a Linux machine and connects to home devices and cameras allows people to manage them.

People who use ZoneMinder always install their own “servers” - there is no central cloud.

I’ve currently implemented a web sockets event notification service as an add on to the “ZoneMinder” software that sends web sockets based notifications to my client when there is a new event.

However, as we know, this web socket gets killed when the app goes into the background in iOS.
(It’s not a VoIP app, nor a location app, nor a content news app, so I can’t keep it alive without the chances of rejection)

So I started looking at push notifications.

The problem however is that all these push notification services require the “server” sending these notifications to also be configured.

In my case, since each user will install their own server (basically download my notification server and install along side their zoneminder server) and use my app, what is the easiest way I can make sure they can set up things to deliver notifications to my app without them having to sign up for apple/google accounts?