@Helzi Hi.
But I still see the 0.6.4 version after I open it
Make sure you are uninstalling / deleting Pencil2D from your app folder.
Additionally this is the direct link for macOSX above 10.13+ https://github.com/pencil2d/pencil/releases/download/v0.6.5/pencil2d-mac-0.6.5.zip
I want to ask will this problem (Can’t export animation if it’s older version of software) also happen on window 10?
In general you shouldn’t have this problem at all, and you should be able to export in all platforms with 0.6.5 as long as your OS is relatively recent. Windows 10 should not exhibit this problem, but sometimes people will report difficulties with Windows 10 that are beyond our scope of support. For them we have this guide specifically [Guide] How to Train Your Pencil2D (Windows)
And we also have a quick post on windows error solutions that is pinned here VCRUNTIME140_1.dll / MSVCP140.dll Missing? Help - #2 by JoseMoreno