Deductions & credits

It should.  I recommend following the steps below to ensure you are able to take a $300 adjustment to income for cash donations while taking the standard deduction in 2020.

You will make this entry in the Federal interview section of the program.

1. Select Deductions & Credits
2. Scroll down to All Tax Breaks and select Charitable Donations
3. Select Start to the right of Donations to Charity in 2020
4. Proceed to enter the details of your charitable cash contribution by entity as applicable in this section.
5. Once you have completed entering your details, select Done with Charitable Donations

Continue through the screens until you see the screen titled Charitable Cash Contributions under Cares Act.  You will be able to confirm the amount of your cash contributions on this screen.

Your input in both of the sections above will ensure you are either able to take the deduction if you are able to itemize, or will pick up the adjustment if you are taking the standard deduction.