Deductions & credits

We got the letter from the IRS.  They did not change our Adjusted Gross Income.  They changed the charitable deduction down to 60%.  IRS Publication 52 - in discussing the 100% limit for 2020 for cash contribution - states as a requirement that "The taxpayer elected to have this limitation apply to such contribution."  TurboTax Deluxe did not have a question about selecting the limit.  How do I know if our file was transmitted with the selection made?  Turbo Tax online doesn't even recognize that we've already filed our return and the IRS accepted it!