How to get column value of key in JOLT

[#1]

I'm looking for breaking following nested JSON file and transform it into a SQL prepared format.

Input JSON file:

{
  "Product1": {
    "Purchase": 31
  },
  "Product2": {
    "Purchase": 6213,
    "Cancel": 1988,
    "Change": 3702,
    "Renewal": 5934
  }
}

Desired output: 

[
  {
    "product": "Product1",
    "Purchase": 31
  },
  {
    "product": "Product2",
    "Purchase": 6213,
    "Cancel": 1988,
    "Change": 3702,
    "Renewal": 5934
  }
]

[#2]

Hi,

Try the following:

[
  {
    "operation": "shift",
    "spec": {
      "*": {
        "*": "[#2].&",
        "$": "[#2].product"
      }
    }
  }
]

If that helps please accept solution.

Thanks