Key copies will open door, won’t turn in ignition

As you found out, a cut key at a hardware store will work for the locks in the door, but you need a key with a transponder chip that is programmed to the cars ignition for it to start. The anti theft system is prohibiting from you starting the car without it. Have a locksmith cut you a proper transponder key and program it to the car. A Kia dealer can do the same. Get a second or third key made so you don't have to go through this again if you lose one.