Check Kia Sephia 1998

Broken ignition key inside the sheet:
Buy another Kia Sephia Shock that was walking
then I took the sheet, a kind of magnetic bowler that I suppose is the one who reads the key code, more in immobilizer that is a box where it connects everything that comes from the sheet.
The car doesn't want to start ...
opinions?

You have to configure key so that the immobilizer authorizes ignition

It is not supposed that the key that came with the key + sheet + immobilizer of the hit car should work

Do not start you because although the key, the code reader and the immobilizer unit are from the same vehicle, the immobilizer communicates with the engine control unit, and the engine control unit does not "know" anything to the immobilizer that you have mounted and that is why it ignores it and does not start. You have to encode the new key to recognize the engine control unit, she is the one who at the end lets her or not.

What Joymar tells you is correct, you must mount the ECU also (because it recognizes the immobilizer and its key) everything must be paired, that is to say key, immobilizer and ECU of the same car, if not, you will have to reprogram key. Greetings!!