Convert charlist to string recursively

Hello. I need help from you
First of all, I have a return value from the neo4j database like this:

%{
  'records' => [
    %{
      'category' => 'NODE',
      'id' => 83,
      'key' => 'm',
      'labels' => ['Match'],
      'properties' => %{'bracket_id' => 1, 'depth' => 1}
    }
  ],
  'results' => %{
    'm' => %{
      'category' => 'NODE',
      'id' => 83,
      'key' => 'm',
      'labels' => ['Match'],
      'properties' => %{'bracket_id' => 1, 'depth' => 1}
    }
  }
}

The type of keys and values are charlist, not string(sometimes the value is integer though). I’d like to convert those charlist keys and values into string all!
Then, the data I want is like this:

%{
  "records" => [
    %{
      "category" => "NODE",
      "id" => 83,
      "key" => "m",
      "labels" => ["Match"],
      "properties" => %{"bracket_id" => 1, "depth" => 1}
    }
  ],
  "results" => %{
    "m" => %{
      "category" => "NODE",
      "id" => 83,
      "key" => "m",
      "labels" => ["Match"],
      "properties" => %{"bracket_id" => 1, "depth" => 1}
    }
  }
}

I think I have to make a function that converts charlist into string recursively, but I don’t have an implementation idea. Because I’d like to convert only charlist, not all list. Please help me if you have a solution for it. Thank you.