After you file

MindyB, Thank you so much for your reply. It is very reassuring. I am in Pennsylvania and also must file a local income tax return. Do you know if the same process is to be followed for my local income tax return, (i.e., rather than amend my 2021 local return, would I instead amend my 2022 return)? If so, do you know how I would do that? My municipality uses Keystone Collections Group. Would I report it on line 11 "Quarterly and Extension Payments/Credit From Previous Year"?