Where are notifications sent if I have the Zucoin wallet on multiple devices?

Notifications go to the last device where you enabled them.

If you get a new phone and restore your Zucoin wallet from a backup, simply enable notifications there and it becomes the new primary device.

The Zucoin wallet app automatically determines which device should receive notifications, so you don't need to manually coordinate between devices.

More on this topic:

How do I turn on push notifications?

How do I move my wallet to a new device?

Zucoin releases mega update, one-tap notifications, sub-second transaction speeds