PositionOpenedEventArgs.Position

public Position Position {get;}

positionOpenedEventArgs.Position: Position

protected override void OnStart()
{
    Positions.Opened += OnPositionsOpened;
    ExecuteMarketOrder(TradeType.Buy, SymbolName, 10000, "myLabel");
}

private void OnPositionsOpened(PositionOpenedEventArgs args)
{
    var position = args.Position;
    Print("Position {0} opened at {1}, volume: {2}", position.Id, position.EntryPrice, position.VolumeInUnits);
}

def on_start(self):
    api.Positions.Opened += self.on_positions_opened
    api.ExecuteMarketOrder(TradeType.Buy, api.SymbolName, 10000, "myLabel")

def on_positions_opened(self, args):
    position = args.Position
    api.Print(f"Position {position.Id} opened at {position.EntryPrice}, volume: {position.VolumeInUnits}")