"Software is using just $300. Am I missing something?"

Yes; read the IRS info:

https://www.irs.gov/newsroom/special-300-tax-deduction-helps-most-people-give-to-charity-this-year-e...

https://www.irs.gov/newsroom/most-taxpayers-can-deduct-up-to-300-in-charitable-contributions-without...

And the Program is doing it right. That makes 4 times you have learned this from this forum. But going to the IRS source, or the 1040 Instructions, or the Charitable Pub, would probably work well, too.