@sjrcpa thank you. It could have been used on the 2020 return. I wasn't sure if it is required to amend 2020 or if it can just be put on 2021 since prior preparer missed it. Trying to avoid amending 2020 if possible.

Not sure if this credit is like depreciation where if you don't get it in they year you're supposed to you lose it so must amend.