I don't know what you mean by "discounting."
ItsDeductible is an online tracking site for your donations during the year and has nothing to do with income taxes. When your donations are imported into Turbotax, Turbotax will apply the rules in effect at the time.
If you are trying to use the current version of Turbotax installed on your own computer, you need to be patient. The first release of the program is missing many of the tax law changes for 2020, they will be fixed in updates before filing is open in January.
