Fulfillment API Error

Hi,

I am getting the following error hen I try to fulfill an order.

{
“errors”: {
“fulfillment”: “Required parameter missing or invalid”
}
}

Josn is as follows:
{
“fulfillment”: {
“location_id”: 19806191686,
“tracking_number”: “123456789”,
“tracking_company”: “TNT”,
“line_items”: [{
“id”: 9700044964015
},
{
“id”: 9700044996783
}]
}
}

How can I understand what parameter is missing or invalid?

‘X-Request-ID’: ‘9a2de63d-8796-4214-ad55-d69c4e71d777’,

I just found the issue. I was sending the data as text but not JSON.

After using the following code, it worked.

data_json = json.dumps(my_json)