Fulfillment API request returning error "The required line_items_by_fulfillment_order field is missi

Trying to create a fulfillment by line item in postman, which worked previously, but is now returning the error

“The required line_items_by_fulfillment_order field is missing.”

Here is the code:

{
“fulfillment”: {
“message”: “The package was shipped this morning.”,
“notify_customer”: “true”,
“tracking_info”: {
“number”: “9241990361700120347077”,
“url”: “https://tools.usps.com/go/TrackConfirmAction_input”,
“company”: “USPS”,
“line_items_by_fulfillment_order”: [
{
“fulfillment_order_id”: “6058467131647”,
“shop_id”: “62443585791”,
“fulfillment_order_line_items”: [
{
“id”: “12878144831743”,
“quantity”: “1”
}
]
}
]
}
}
}

Any help would be greatly appreciated!

Update: I removed the shop_id after realizing that isn’t part of the scope. Still getting the error though.

I figured out the problem. line_items_by_fulfillment_order was incorrectly nested in tracking_info.