Combining sheets dates to summary - Formula Error

Good day, All.

I have worksheets from 1st to 18th Oct 23 and want to retrieve quantities from particular cells from the worksheet but I am a bit stuck on the summary page as I could not change the formula to drag down dates from each worksheet on the summary and need to manually input the dates to retrieve the quantities.

Attached is the workbook (Under summary highlighted in Yellow)

Thank you very much for your guidance.
Ravind