I would do it something like this:

  def transform([{_, _}|_] = list) do
    Enum.reduce(list, %{}, fn {key, val}, map ->
      Map.put(map, key, transform(val))
    end)
  end
  def transform({[{_, _}|_] = list}), do: transform(list)

  def transform(val), do: val

And then call it with just

transform/1

And the result would be something like:

%{
  "App-Version" => "version_here",
  "Body" => %{
    "CurrentTime" => "2023-02-23T16:40:13+05:30",
    "Identification" => %{
      "A" => "A-Val",
      "B" => "B-Val",
      "C" => "C-Val",
      "D" => "D-Val"
    },
    "Names" => ["Name1", "Name2"]
  },
  "Method" => "method-here",
  "TX-ID" => "tx-id-here",
  "_id" => "idhere"
}