How to use objects in fest?

Question

JSON

Hello everyone... I have a question about the fest
there is a large and thick object, there is this: "engine":{"id":0}
there is a fest, none of the options helped:
profile.get('engine-> id')profile.get('engine=>id')profile.get('engine.id')
did not help in any way, I didn't find anything special on the fest site...
I will be grateful) thanks)