Should I file 2023 amended return before or after filing 2024 return? I am going to amend 2023 to carry-back excess foreign tax credit. Not sure which to file first.

[DawnC]

It doesn't matter; you can file your 2024 return before or after you file the amendment for last year.   I'd file the 2024 return before doing the amendment, but you don't have to.   How to Amend a Prior Year Tax Return

In order to carry back the extra foreign tax credit and claim an additional refund for last year, you'll need to have foreign source income 

from last year that wasn't used for a credit.