it depends on whether anything on the 2021 return would affect the 2022 return. if so, then you may later need to file an amended 2022 return. if nothing on 2021 will affect 2022, then its your choice as to whether to file 2022 now (by midnight your time) or extend. Any balance due is due by midnight (no extension on paying). if extended, you have until 10/15/2023 to file 2022 by which time you should know for sure about 2021s affect on 2022.