Sumif with wildcard challenge

I am trying to total the number of units (Quantity and Back Fill) for each month for a certain product. My data only provides an invoice number to use as a reference rather than the invoice number and product name. I am trying to figure out the formula for solve for this. Attached is my excel file with a sample bit of data. The yellow fields are the ones I am looking to resolve. Note that my actual file contains data validation lists, so ideally I would like the formula to reference the cell row and column where the invoice number resides. This makes it even trickier given it requires a wildcard entry.

Thanks in advance.

Try the following formula in cell E3.

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Let me know if that helps!

If want to sum both Col. B and C (Quantity and Back Fill), perhaps try:

E3: =SUMPRODUCT(($B$9:$B$27+$C$9:$C$27)*(LEFT(E$9:E$27,LEN(E$2))=E$2))

and copy across to G3.

Hi. Thank you but that formula did not work. The one from Berian below did so I am good to go. Thanks!