my imessage security key:
APKTIDxTTWJMm-i7SapNDOXTO6Ek41RYY6x0uQCFsHYKWdAZ1I1g

what is it?
https://support.apple.com/118246

iOS/iPadOS ≥17.2, watchOS ≥10.2, macOS ≥14.2 are required on ALL your devices !! btw