XTB API JSON cannot modify existing trade position - json

Question

I am using a xAPI Playground for testing, link here:
https://playground.xapi.pro/
I want to edit/modify existing position with command: tradeTransaction
Documentation says to modify existing position I should use "type" as 3 and "cmd" should match existing position (0 for BUY and 1 for SELL)
{
"command": "tradeTransaction",
"arguments": {
"tradeTransInfo": {
"cmd": 1,
"customComment": "Some text",
"expiration": 0,
"order": order_number_as_int ,
"price": open_price_as_double,
"sl": my_double_value,
"tp": my_another_double_value,
"symbol": "f.e. OIL.WTI",
"type": 3,
"volume": 0.01
}
}
}
Error code
{
"status": false,
"errorCode": "SE199",
"errorDescr": "Internal error"
}
All possible data collected from API about existing position:
{'cmd': 1, 'order': 474325736, 'digits': 2, 'offset': 0, 'order2': 474325838, 'position': 474325736, 'symbol': 'OIL.WTI', 'comment': '', 'customComment': '', 'commission': 0.0, 'storage': 0.0, 'margin_rate': 0.0, 'close_price': 76.65, 'open_price': 76.57, 'nominalValue': 0.0, 'profit': -3.56, 'volume': 0.01, 'sl': 80.0, 'tp': 70.0, 'closed': False, 'timestamp': 1676665564666, 'spread': 0, 'taxes': 0.0, 'open_time': 1676663063081, 'open_timeString': 'Fri Feb 17 20:44:23 CET 2023', 'close_time': None, 'close_timeString': None, 'expiration': None, 'expirationString': None},
API documentation is here:
http://developers.xstore.pro/documentation/#tradeTransaction
Ofc I tried every possible value in "cmd" and "type" but it does not help.
Error code sometimes are diffrent, f. e:
{
"command": "tradeTransaction",
"arguments": {
"tradeTransInfo": {
"cmd": 3,
"customComment": "Some text",
"expiration": 0,
"order": 474325838,
"price": 0,
"sl": 0,
"tp": 0,
"symbol": "OIL.WTI",
"type": 3,
"volume": 0.01
}
}
}
Error code:
{
"status": false,
"errorCode": "BE4",
"errorDescr": "remaining nominal must be greater than zero"
}
Any ideas what I can do wrong?
I am in touch with XTB support, still waiting for response.
Thanks in advance for any help!