Use the Find My app to locate a missing device or item
https://support.apple.com/en-ca/guide/findmy-mac/fmm0e3934777/mac
Turn off Lost Mode on a device
When you find your lost device, turn off Lost Mode.
- In the Find My app
on your Mac, click Devices. - In the Devices list, select the device you marked as lost, then click the Info button
on the map. - Under Mark As Lost, click Pending.
- Click Turn Off Mark As Lost.
- Click Turn Off to confirm.
You can also turn off Lost Mode on iCloud.com or from your iPhone, iPad, iPod touch, or Apple Watch by entering the device’s passcode (the one you use to unlock your device). For iPhone Leather Wallet, you can turn off Lost Mode by attaching the wallet to your iPhone.
If you forget your device passcode, you can recover it using Find My iPhone on iCloud.com. See Use Lost Mode in Find My iPhone in the iCloud User Guide.
Unlock a Mac
When you find your lost Mac, enter the numeric passcode on the device to unlock it (the one you set up when you marked your Mac as lost).
Note: You can’t turn off Mark As Lost remotely from another Mac. You can only turn it off directly on the Mac that you marked as lost.
If you forget your device passcode, you can recover it using Find My iPhone on iCloud.com. See Use Lost Mode in Find My iPhone in the iCloud User Guide.