How to turn Stolen Device Protection on or off
About Stolen Device Protection for iPhone - Apple Support
To turn on Stolen Device Protection, you must use two-factor authentication for your Apple Account and set up or enable the following on your iPhone: a device passcode; Face ID or Touch ID; and Significant Locations* (Location Services).
You also need to have Find My turned on, and you can't turn it off while Stolen Device Protection is enabled.
You can turn on Stolen Device Protection in Settings:
- Go to Settings, then tap Face ID & Passcode.
- Enter your device passcode.
- Tap Stolen Device Protection, then turn Stolen Device Protection on or off.

When you restore from iCloud Backup or transfer directly from a previous iPhone
to a new one, your device settings — including Stolen Device Protection —
are also restored. After a short delay to sync familiar locations from
iCloud, the Stolen Device Protection security measures automatically
resume on your new device.