Which tax year?
If 2019 desktop software...the TTX validation service appears to be shut down for that year. They aren't supporting 2019 anymore.
The 2020, 2021,2022 desktop installations are still working (I installed those on a new laptop last week).
2023 should also work, but I won't try that myself for another month or two,
____________*Answers are correct to the best of my knowledge when posted, but should not be considered to be legal or official tax advice.*
