Hi HazelLIU95 ,
Since changing the Customization would still require you to edit forms, I'd generally just recommend editing the form using the Report Designer. (Most businesses don't change their bank accounts often.)
There are a variety of resources online about the report designer, designers can be tricky so if you get stuck I recommend asking your implementer to set it up for you. (They'll be able to do other cosmetics for you if there's anything needed).
With that said, here are some resources if you do want to go down the editing your own reports/forms route.:
YouTube search for "Acumatica Report Designer" got me this, I haven't watched it more than a couple of seconds, but it seems like the correct kind of tutorial if you do want to learn some report editing for yourself:
https://www.youtube.com/watch?v=8xVGNYPWZ6U
Acumatica also have a full training course available (S150), which is how I learnt how to work with the designer initially:
https://openuni.acumatica.com/courses/reporting/s150-reporting-report-designer/
Last hint:
If searching for information about this, you might want either "forms" or "Report designer" as your search term, just beware that 'form' will bring up a bunch of how to customize a screen information.