how can i store security hub findings-imported key value in variable in input transformer

i was using input transformer to have specific key value but I got stuck while fetch one key value i.e Id in resources , if you can refer sample event there on below id key is there and I want to fetch value for that key value, if anyone can help me here please. i tried , "id": ""$.detail.findings[0].Resource.id" but this didn't worked.