Push notifications triggered by user location?

help
1

How to have my app send a push notification triggered by the user’s location, when the user has the app running in the background?

2

If you have the users location, let the user subscribe to a query that matches that location. Can have a session variable or a db table that ticks off notification being received (userId/notificationId)

3

Thanks. But how to then have this notification show up when the app is in the background?