Loop stores data in Apple HealthKit used by the algorithm. So, the phone running Loop must be logged in with that user's Apple ID.
There are a few approaches to this that can be useful. In all cases, the Loop app would be restored using the same TestFlight entitlement already established with the Looper's AppleID.
A donor phone can be used, such as owned by a family member or friend. In this case, their apps and data will be restored when the Looper logs in to that phone. Following this process, the Looper installs Nightscout from TestFlight (which has been restored to the phone). The HealthKit data and Loop settings will be restored as well. Then, the Looper would start the Loop app, enter Nightscout credentials, import current Loop profile settings, connect the CGM, and start a new pod. The phone no longer has the identity of the former user. This includes apps and data such as email, calendar, browser configuration, etc.
A "standby" phone can be used. In this case, a faster 'warm start' can be achieved by previously configuring and syncing the phone as described above. It is a good idea to keep this phone charged and turn it on periodically to allow it to synchronize with iCloud. This will ensure the phone actually works when needed, and that it will take less time to synronize current health data. This can be an older phone you may already own and have replaced with a newer phone or one purchased for this purpose. That phone must be capable of running iOS 15 or greater.
A replacement phone can be obtained, new or used. In this case, it may take a while to procure the phone. Then, the steps outlined above will be followed. During the period without Loop, the active pod will run the scheduled basal until the pod expires or runs out of insulin.
Other methods for ensuring continuity of insulin therapy include having the Dash PDM available to revert to that treatment method or having long and short-term insulin and syringes available to revert to Multiple Daily Injections (MDI).
To learn more, T1Pal subscribers can schedule a personal T1Pal Success Workshop at this link:
https://calendly.com/t1pal/t1pal-success-workshop
We use Zoom screen sharing to resolve any issues you may have. This workshop also provides the opportunity for a full demonstration of T1Pal Nightscout, including the dashboard, reporting for historical review, the care portal, remote controls, and more. We'll be able to help you configure various uploaders and followers and answer any other questions.