How to program immobilizer without going to the dealer?

[pikachu]

Hi,

Is it really not possible to program the immobilizer code into the ecu without going to the dealer?

I'm driving a MY03 EU WRX. My orginal ecu has Ecutek. I've bought another MY03 EU WRX ecu for me to try tuning using opensource but I can't start my car due to the immobilizer.

How does the ECUTEK tuners program the immobilizer when their customers swap ecus?