where can I locate the fuel pump/filter in my 2018 Chrysler Pacifica touring?

The code tells you where the problem is not what to replace . It still needs to be diagnosed . If you're unsure take it to a good shop . I doubt it's the filter , could be a ground or regulator .

5 years is a little early to loose a fuel pump, but it is a Chrysler product so anything is possible. You need to run diagnostics on the code before just slapping parts on it. If the diagnostics show it’s a bad pump then the pump is in the fuel tank, so the tank has to be removed to replace the pump assembly, check the fuel pump connector for burnt contacts and don’t forget to replace the fuel pump relay at the same time.