JSON character export

When you export a character from roll20 on the export tab you get a json file with a list of attributes like this:

        {
            "name": "initiative_bonus",
            "current": 2.15,
            "max": "",
            "id": "-M2K-9Y4FbbCEhpfr7DK"
        },

Each one of those attributes has an "id" field that appears to be unique, what is this id and what is it used for? Does it have to be set to a specific thing? What happens if you change it? There's also an "oldId" at the top of the file, same deal for that one?

I believe you are likely using an unsupported third party product. There is normally no Export Tab on a character sheet.