You have two options, you can choose to put them in either NC and COM or NO and COM. Polarity does not matter.
If you choose NC and COM that’s a “Closed” connection that opens on alarm, so you’ll want to set your Notification to be to notify on “Loop Open”.
If you choose NO and COM that’s an “Open” connection that closes on alarm, so you’ll want to set your Notification to be to notify on”Loop Closed”.