Ionic 5 listen for web requests

I have an app that will need to listen for web requests. Essentially, it needs to be subscribed to a notification that may come from someone else’s version of the app. I believe the way to do this would be to have a backend server which my app periodically checks for messages intended for it.

While that would work, is there a built-in way for an ionic app to be told it has messages intended for it?