Hello,
I'm thinking your hybrid battery is dead (drained or faulty).
The service battery initializes everything (12v system) and the hybrid battery starts the engine using the hybrid drive system like a starter.
In other words, you don't have a normal starter on your vehicle, so failing to crank the engine is nearly certainly an issue with the hybrid system.
Please, don't try to service the system yourself without a hybrid certified friend to offer assistance. If there is any power stored in the hybrid battery it can kill you if mishandled.
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