Have you completed this year's return, and, did you have a tax liability for 2019. If so, I think your credit is limited to the lesser of the credit or the tax liability. In other words, if you owed no taxes for 2019, you have to carry forward the entire credit to 2020. If you have a $1,000 credit & your pre-credit tax liability is $600, you get to claim a $600 credit for 2019 and the difference of $400 is carried forward until 2020.
