Dynamically populating picklist using v7 API is throwing INVALID_DATA error

Dynamically populating picklist using v7 API is throwing INVALID_DATA error

Hi,

So basically, I've tried all sorts of solutions but to no avail. This is the error I kept on getting:

{
    "code": "INVALID_DATA",
    "details": {
        "expected_data_type": "jsonobject"
    },
    "message": "body",
    "status": "error"
}


And this is the object I'm passing following the v7 documentation:
const obj = {
    "fields": [
        {
            "pick_list_values": [
                {
                    "display_value": "North_East",
                    "actual_value": "IN_North_East"
                } //Adding options to an existing picklist         
            ]
        }
    ]
}