How do I add an AirTag that's already been used?
How to connect used air tags
[Re-Titled by Moderator]
iPhone 7, iOS 13
Question marked as
The used AirTags MUST first be completely removed from the prior owner’s AppleID.
If an item or device is connected to another Apple ID – Apple Support (AU)
Once that is accomplished, they can then be setup as outlined here:
Add an AirTag to Find My to keep track of personal items - Apple Support