How can I get unique identifier IOS in unity?

We needs to get a unique identifier from ios devices, but Apple will reject all apps that using UDID. What’s the solution in Unity?

There is a API SystemInfo.deviceUniqueIdentifier, but after I removed app and re-install again, Systeminfo.deviceUniqueIdentifier value was changed everytime.

Systeminfo.deviceUniqueIdentifier will not deliver the Device’s UDID.
No iOS app can access the UDID anymore.
Under ios you can get the AdvertisingIdentifier

Be aware the the user can decide to change them in the iOS advertising Options.