your package is in a parcel locker. Check the key tag for the corresponding locker number and open that locker. If you live in an apartment/condo, contact your building's management office to see if the package was left with them.
Schedule a Redelivery for a date when someone will be at home to sign for it; use the package's tracking number or the barcode number on the Redelivery notice. If delivery to a USPS® Smart Locker is available, it will be indicated on the Redelivery notice. Pick it ...