2019 will have a Federal Carryover Worksheet that you can enter the capital carryover losses.

Activate the 1040X in 2019 (click the 2019 box at the top of the form) then go to the Federal Carryover Worksheet and enter the capital loss carryover (its on page 2 of the worksheet, Lines 12 and 13) and it should make the adjustment on the return.