@unmesh59
I didn't completely understand what you said, but if you're trying to fill in the values that you blanked out, you will have to manually re-enter them. Revisit the Foreign Tax section, choose to get credit this time, acknowledge that there are carryovers, etc.
1) You can get the numbers from last year's saved return and worksheets (if you have them), or
2) You can start a new duplicate return and once you import from 2020, flip on the Forms button, choose the form you need and the numbers will be there. No need to go through all the other interview and entry sections. Print the forms you need and manually copy to the "original" return. Then just delete this duplicate return.
