Toitboxes arrive unclaimed with a QR code on the E-Ink display. How to claim a Toitbox is explained in here
If the QR code is not visible, it is also possible to claim a Toitbox manually by using the hardware ID of the device, which can be found if you remove the lid on the back of the Toitbox.
The hardware ID is represented as a 36 characters UUID (32 hexadecimal characters and 4 hyphens).
Read a description of how to manually claim a Toitbox here
Navigate to the remote Toit Console, select the 'Claim device' menu item. In the claim dialog, type the hardware ID of the Toitbox, and click 'Claim'.