Need guidance with WhitelistPlatforms

Hi there guys, hope you are okay…
just need some guidance on how i would select my WhitelistPlatforms.

I just finished the Packaging (for testing) of my plugin on Win64 (it fails for Win32). It also fails for Mac and so on…
My question is… do i need a Win32 PC, a Mac, iOS, etc… or do i just Whitelist everything and Epic will build it for me?.

I would want to Whitelist everything, but if i must test the platforms, i would at least want to know why Win32 fails and whitelist that one…

Can someone that has uploaded a CodePlugin share some light on the issue?

Thanks a lot