Get json data from incoming Flask request.json case insensitive

I’m implementing an API (proxy) that accepts incoming JSON POST data in Flask.
I need to process this JSON and after that send it on to a backend API, which was written in another language.

The JSON data will be sent by end-users, and they are used to sending this JSON data case-insensitive. This means that the incoming JSON data will sometimes have uppercase keys/nodes, sometimes lowercase, and sometimes maybe camelcase or pascalcase.

I’m using Flasks request.json to get the data from the request. It is parsed into a Python object, but this object will have case-sensitive keys and values. These will also be nested.

A specific example of how I currently get data is:

data['ORDERS']['authentication']['AccountToken']

But my users might POST:

{
    "Orders": {
        "Authentication": {
            "AccountToken": "C3485D7B" 
        },
    ...

Is there a way to get data['ORDERS']['authentication']['AccountToken'] in such a way that the complete path to that value is case-insensitive?
I understand I can check for each part of the path case-insensitive separately, but that requires a lot of overhead code to get to the right child-nodes.

I saw other solutions: Case insensitive dictionary

I have also tried using CaseInsensitiveDict from the requests library like this:
data = CaseInsensitiveDict(request.json), but that only makes the first level of the object case insensitive actually.

The problem with these solutions is that they deal with dicts, while the JSON data is a dict of objects that can be lists or other objects. The solutions provided don’t work recursively or only on Dicts.

Any help is appreciated.

>Solution :

This function outputs a case insensitive dict, creating it recursively for every entry:

from requests.structures import CaseInsensitiveDict

def case_insensitive_copy(data):
    if not isinstance(data, dict):
       return data
    temp_dict = {}
    for key, value in data.items():
       temp_dict[key] = case_insensitive_copy(value)
    return CaseInsensitiveDict(temp_dict)

d = { "Orders": {
    "Authentication": {
        "AccountToken": "C3485D7B"
         }
      }
    }

d = case_insensitive_copy(d)
print(d['ORDERS']['authentication']['AccountToken'])
>>> C3485D7B