How to file amended return with carry back losses on Section 1256

I have some losses in Section 1256 Futures & Options in 2022/2021 that I want to carry back to 2020. I have overall Capital Gains in Schedule D of my 2020 tax returns. I've been trying to file an amended return with Turbotax, but having trouble to select the right section to input the carried back losses. Any help is appreciated.