Label vs Field Key

If I understand correctly, we must use “LABEL” (display field) nstead of “FIELD KEY” for the column headers in the Google Sheet. Is this true? I have multiple fields on my ‘return authorization form’ that have the same name (“Item” and “Quantity”). In order for the data to map properly to the spreadsheet, I had to rename each display field “Item (1)” and “(Item (2)” and “Quantity (1)” and “Quantity (2)”. This is what the customer sees when they complete the form. It’s confusing. If I was able to map by Field Key they wouldn’t see that on the display and it would still put the correct info into the spreadsheet. Is this possible?