line 6 of Schedule A?
you took a deduction in 2020 rather than a credit. to fix this you would need to amend 2020.
for 2020 if it's $600 or less than in most situations you can take it as a credit without filing form 1116
however, form 1116 would be required if your tax was low enough to produce a FTC carryover. then you may need to amend subsequent years to utilize the carryforward. This is not required if you are willing to forfeit any carryover
