How can KNIME be leveraged to dynamically calculate total sales within user-defined date ranges?

I have a dataset with two columns: ‘Date’ and ‘Sales Amount.’ Using KNIME, I aim to design a workflow that calculates the total sales amount for a user-defined date range. How can flow variables be integrated into the workflow to make it adaptable to different date ranges?

| Date       | Sales Amount |
| 2024-01-01 | 100          |
| 2024-01-02 | 150          |
| 2024-01-03 | 200          |
| 2024-01-04 | 180          |
| 2024-01-05 | 250          |