Adding a phone, iPad or Mac

Settings › Devices › Add an iPhone or iPad shows a code to enter on the phone; then compare codes.

Adding a phone or iPad is one flow, in Settings › Devices › Add a device:

Choose Add an iPhone or iPad…. A short code appears, good for a few minutes and usable once.
In OdinCam on the phone or iPad, choose Pair and enter it. That connects it to your relay account.
It then asks to join your household straight away, and six-digit codes appear on both screens. If they match, confirm on both.

Pairing lets the device reach your cameras through the relay; joining gives it the keys to see the pictures and video, which are encrypted for household devices only.

Another Mac: install OdinCam on it, register it in Settings › Devices with your relay account's enrollment token, then choose Join in its Devices settings and approve it from any device already in the household.

A pairing code that's expired or already used is refused with its own explanation; make a new one. Each device has its own identity: adding a second phone doesn't affect the first.