If you transferred your prior return it should be already filled in.
Enter a Capital Loss Carryover under
Federal Taxes or Personal (Home & Business)
Wages and Income
Then scroll down to Investment Income
Capital Loss Carryovers - Click the Start or Update button
And it should be the remaining 5,000 that was carried over from 2019. (8,000-3,000). You get to first offset the loss against any gains you have each year so that can use more of it up. Then after applying the loss to the current gains you can take a max loss of 3,000 (1,500 MFS)per year. Turbo Tax does all the calculations for you. Just enter the prior year carryover amount.
