There are many reasons why this could be the case, we would recommend checking your courier tracking link.
COLLECTION FROM POST OFFICE
Where Authority to Leave (ATL) was not selected, or, if ATL was selected but a safe place to leave the order could not be identified, the order will typically be taken to a Post Office nearby.
To confirm that has occurred, you can review your order using this more detailed tracking link https://www.nzpost.co.nz/tools/tracking.
LEFT IN A SAFE PLACE
Where Authority to Leave (ATL) is given, the courier will not require a signature for delivery, and will leave the order in a safe place.
If you maintained the ATL selection at check out, we recommend carefully checking your property for the order.