BINGX - Signature verification failed due to signature mismatch

I am trying to Place an Order on /openApi/swap/v2/trade/order using Trades Endpoints of BingX with parameter takeProfit. But I'm just getting the response below:

{code=100001, msg=Signature verification failed due to signature mismatch,please verify our authentication signature and try to run our sample code from the link https://bingx-api.github.io/docs/#/en-us/spot/account-api.html#Query%20Assets, timestamp=1743820085747}

Parameters used:

• symbol : "BTC-USDT"
• type : "TRIGGER_MARKET"
• side : "BUY"
• positionSide : "LONG"
• quantity : "100"
• stopPrice : "XXXX"
• takeProfit: "{"type": "TAKE_PROFIT_MARKET", "stopPrice": 31968.0,"price": 31968.0,"workingType":"MARK_PRICE"}"

Note that it is a success without the parameter takeProfit.

Scenarios:

1. I tried to use URLEncoder.encode and I get the response above.
2. No URLEncoder.encoder will result to code 400
3. Passed the takeProfit as body has the same response above.

Anyone who might know the answer? TIA!