Cancel Multiple Orders Future API

Hi,

I am trying to cancel multiple orders and I am sending the following:
{‘data’: [(‘orderIdList’, ‘[422691743,422691757]’), (‘symbol’, ‘BNBUSDT’), (‘timestamp’, ‘1599469813176’), (‘signature’, mysignature)], ‘timeout’: 10}
to the url https://fapi.binance.com/fapi/v1/batchOrders.
I am getting the error BinanceAPIException: APIError(code=-1022): Signature for this request is not valid.
The thing is that sending to https://fapi.binance.com/fapi/v1/allOpenOrders works perfectly and so does cancel one single order. So I do not get what issue…

Please check this script, which works fine with batchOrders

thanks