Anti-theft mode

Can you try locking and unlocking the car using your remote? Here is a guide to help you reset the system:

https://www.2carpros.com/articles/how-to-reset-a-security-system

Please run down this guide and report back.

Hello, I assume you mean the immobilizer warning light is active? If the car starts for a split second then stalls with the immobilizer light flashing, you will have to scan the vehicle first. Usually you will see a key fault which would indicate the key needs to be replaced and programmed to the vehicle.