Lost every Cruze key?
With no Cruze key left, the HU100 blade is milled to GM's code for the VIN, then the chip and remote, or the push-start fob, go in over the diagnostic port at the car. GM's security access can hold the programmer on a timer, commonly about ten minutes and on some cars repeated, so allow more time than a spare-key visit.
Losing the last key adds $60 to either price: a flip key becomes $165 plus $60, a fob $229 plus $60. Have a license in the owner's name next to the title or current registration. When the Cruze starts on the new key, the missing one is cleared from the car, so it will not start the engine for anyone who picks it up.