c# API to calculate parabolic sar

Hi, I'm trying to use the parabolic sar class in the S# library inside my C# program. My understanding is I need to populate the SAR object with values using the process() method like this:

ParabolicSar psar = new ParabolicSar
            {
                Acceleration = SARSeed,
                AccelerationStep = 0.02M,
                AccelerationMax = 0.2M
            };
            for(int i = 0; i < iBars; i++)
            {
                TimeFrameCandle candle = new TimeFrameCandle()
                {
                    ClosePrice = (decimal)closeArr[i],
                    HighPrice = (decimal)highArr[i],
                    LowPrice = (decimal)lowArr[i],
                    OpenPrice = (decimal)openArr[i],
                };
                psar.Process(candle);
            }
            
            var sarValue = psar.GetValue(shift);

But I am getting no values and the container is empty. How can I fill it with data to get the correct PSAR value at a specific candle instance. Your help is appreciated.

Thank you