What are the alternatives for FCM google?

Question

Android

Good afternoon.
We have an android application for a corporate network.
We want to add push notifications.
FCM from Google is not suitable for us, due to the lack of work with a proxy and due to restrictions on Internet access.
Are there any alternatives.
The ideal option is that it can be deployed on a local network and does not need Internet access

Answer 1

You can write your own notification service.