More then likely this is an issue with the interlock solenoid. However, here is a guide that will help with this issue in more general terms:
https://www.2carpros.com/articles/ignition-switch-wont-turn-stuck
Below you will find the process for the solenoid which is what I suspect will have to be replaced.
The theft light is blinking most likely because the ignition is not turning. It is normal for it to flash slowly while the key is off.
Please run through this info and let us know if you have other questions. Thanks
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Friday, July 16th, 2021 AT 8:19 AM