API FAPI error signature BUY token

API Futures API
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1

Hi.

I use python 3.9.4 with BINANCE API.
I use the function “send_signed_request” of this sample : https://github.com/binance-exchange/binance-signature-examples/blob/master/python/delivery-futures.py

I have no probleme to send requests for get account info or price market.
But when I want to make new order :

  • Postman
    With Postman there is no probleme with : {{url}}/fapi/v1/order?symbol=LTCUSDT&side=SELL&positionSide=BOTH&type=MARKET&quantity=0.150&timestamp={{timestamp}}&signature={{signature}}

  • Python
    with pyton :
    https://fapi.binance.com/fapi/v1/order?symbol=LTCUSDT&side=BUY&positionSide=BOTH&type=MARKET&quantity=0.084&timestamp=1620408669292&signature=7fdb0.....

I have error messages :
{'code': -1022, 'msg': 'Signature for this request is not valid.'}

Note:
I maked a little change on function “send_signed_request” because ? became & just behind timestamp
Before :

def send_signed_request(http_method, url_path, payload={}):
…
if query_string:
query_string = “{}&timestamp={}”.format(query_string, get_timestamp())
else:
query_string = ‘timestamp={}’.format(get_timestamp())

url = BASE_URL + url_path + ‘?’ + query_string + ‘&signature=’ + hashing(query_string)
…

After :

def send_signed_request(http_method, url_path, payload={},**defaultItemTimestamp='?'**):
if query_string:
    query_string = "{}"+**defaultItemTimestamp**+"timestamp={}".format(query_string, get_timestamp())
else:
    query_string = 'timestamp={}'.format(get_timestamp())

url = BASE_URL + url_path + **defaultItemTimestamp** + query_string + '&signature=' + hashing(query_string)

So, with this function it’s always ok for get account info or price market, but KO for make new order

I not understand…

Thank for your help