Updating values based on interactive line position

I have a strategy which the user inputs prices and it will draw the line on the chart. I want to be able to move the lines on the chart and have it update the price values which are used for order entry.

I am not sure the correct method but this is what i am trying to use:

    protected override void OnDrawObjectsCallback(string tag, object sender, EventArgs args)
    {
        if (State != State.Realtime || sender == null)
            return;

        if (sender is HorizontalLine line)
        {
            double price = line.StartAnchor.Price;

            switch (tag)
            {
                case "LongLevel1":
                    UpdateLongLevel(1, price);
                    break;
                case "LongLevel2":
                    UpdateLongLevel(2, price);
                    break;
                // Add cases for other Long Levels as needed
                case "ShortLevel1":
                    UpdateShortLevel(1, price);
                    break;
                case "ShortLevel2":
                    UpdateShortLevel(2, price);
                    break;
                // Add cases for other Short Levels as needed
                case "Pivot1":
                    UpdatePivotLevel(1, price);
                    break;
                case "Pivot2":
                    UpdatePivotLevel(2, price);
                    break;
                    // Add cases for other Pivot Levels as needed
            }
        }
    }

This gives me an error that there is no suitable method for override. Could you give me any suggestions or if this is not the correct way?