JSON_LISTINGS_FEED error 4002005 no header

[alesconti]

I am having a big problem with the JSON_LISTINGS_FEED feed type. This is the content of the feed I send:
{
"header": {
"sellerId": "AXXXXXXX",
"version": "2.0",
"issueLocale": "en_US"
},
"messages": [
{
"messageId": 24096,
"sku": "101_1018809",
"operationType": "PATCH",
"productType": "PRODUCT",
"patches": [
{
"op": "replace",
"path": "/attributes/fulfillment_availability",
"value": [
{
"fulfillment_channel_code": "DEFAULT",
"quantity": 51,
"lead_time_to_ship_max_days": 1
}
]
}
]
}
]
}
and this is the result:
{"header":{"sellerId":"","version":"2.0","feedId":"1376880020146"},"issues":[{"code":"4002005","severity":"ERROR","message":"L'attributo 'header' è obbligatorio, tuttavia non è presente."}],"summary":{"errors":1,"warnings":0,"messagesProcessed":0,"messagesAccepted":0,"messagesInvalid":0}}

I can't find a solution.
please help me

thanks

[saleweaver]

how do you send this?

[alesconti]

Feeds(
credentials=credentials,
marketplace=mkt
).submit_feed(
feed_type= feed_type,
file = f,
content_type = 'application/json; charset=UTF-8'
)