Binance TR API Withdraw Endpoint – Invalid Signature Error

I’m getting an “Invalid signature” error when trying to use Binance TR’s /open/v1/withdraws endpoint.

How can I solve this error ?

{
    "code": 3702,
    "msg": "Invalid signature.",
    "timestamp": 1734095521602
}

Here’s my code:

import hmac
import hashlib
import time
import requests
from urllib.parse import urlencode
from typing import Optional, Dict

class BinanceTRClient:
    def __init__(self, api_key: str, secret_key: str, base_url: str = 'https://www.binance.tr'):
        self.api_key = api_key
        self.secret_key = secret_key
        self.base_url = base_url

    def _generate_signature(self, params: Dict) -> str:
        query_string = urlencode(params)
        signature = hmac.new(self.secret_key.encode('utf-8'), 
                           query_string.encode('utf-8'), 
                           hashlib.sha256).hexdigest()
        return signature

    def withdraw_try(self, amount: float, bank_account: Dict[str, str], 
                    client_id: Optional[str] = None, recv_window: int = 5000) -> Dict:
        endpoint = "/open/v1/withdraws"
        params = {
            'asset': 'TRY',
            'amount': str(amount),
            'address': bank_account['iban'],
            'accountHolder': bank_account['account_holder'],
            'bankName': bank_account['bank_name'],
            'timestamp': str(int(time.time() * 1000)),
            'recvWindow': recv_window
        }
        
        print("Request Parameters:", params)
        signature = self._generate_signature(params)
        params['signature'] = signature
        print("Generated Signature:", signature)

        headers = {
            'X-MBX-APIKEY': self.api_key,
            'Content-Type': 'application/x-www-form-urlencoded'
        }
        
        print("Request Headers:", headers)
        print("Full URL:", f"{self.base_url}{endpoint}")

        try:
            response = requests.post(
                f"{self.base_url}{endpoint}",
                headers=headers,
                data=params
            )
            print(f"Full Response: {response.text}")
            
            response_data = response.json()
            if 'code' in response_data:
                raise BinanceTRException(f"API Error: {response_data['msg']}")
            return response_data
            
        except requests.RequestException as e:
            raise BinanceTRException(f"Connection error: {str(e)}")

class BinanceTRException(Exception):
    pass

def main():
    api_key = ''  # Your API key here
    secret_key = ''  # Your secret key here
    
    client = BinanceTRClient(api_key, secret_key)
    
    try:
        withdraw_request = client.withdraw_try(
            amount=100.00,
            bank_account={
                'account_holder': '', # account holder
                'iban': '',  # Your IBAN here
                'bank_name': '', #bank name
            }
        )
        
        print("Withdrawal request successful:")
        print(f"Transaction ID: {withdraw_request['data']['withdrawId']}")
        print(f"Timestamp: {withdraw_request['timestamp']}")
        
    except BinanceTRException as e:
        print(f"Withdrawal error: {e}")
    except Exception as e:
        print(f"Unexpected error: {e}")

if __name__ == "__main__":
    main()