Futures new order api returning "Order does not exist" error message

Hi, I am trying to place a new order through POST /fapi/v1/order using python requests.
Whenever I post, I get error code -2013 with the message “Order does not exist”.
The weird thing is that this error message seems like a message for GET /fapi/v1/order when there is no order exists.
So I checked response.history and response.request, and noticed that there have been 301 redirection, and the request was GET.
What am I doing wrong?

Following is a snippet of my code.

headers = {'X-MBX-APIKEY': MY_API_KEY}
url = "https://binance.com/fapi/v1/order"
query = {
    'symbol': 'BTCUSDT',
    'side': 'BUY',
    'type': 'MARKET',
    'quantity': 0.001,
    'timestamp': some_timestamp
}
query['signature'] = signature_of(query)
query_string = urlencode(query)

r = requests.post(url, params=query, headers=headers)

print(r.json())  // {'code': -2013, 'msg': 'Order does not exist.'}
print(r.history)  // [<Response [301]]
print(r.request)  // <PreparedRequest [GET]>

The base url for futures is https://fapi.binance.com

Thanks!
It really was a stupid mistake:)