JSONDecodeError: Expecting ',' delimiter: line 1 column 43 (char 42)

Your JSON is invalid, it has : tokens in an array:

"result": ["0": "24", "1": "43", "2": "56"]
#             ^          ^          ^

and

"result": ["0": "44", "1": "29", "2": "34"]
#             ^          ^          ^

Fix your JSON input; either replace those colons with commas, remove the "0":, "1":, and "2": 'indices', or replace the [...] array brackets with {...} JSON object braces.