How to build a installer with electron-builder.yml that not covering all directory?

[qeawa-Jax]

• Electron-Builder Version: 24.13.3

• Node Version: 18.14.2

• Electron Version:31.0.2
• Electron Type (current, beta, nightly):current

• Target: windows exe

In my application, I have some extra files packaged by NSIS script installer.nsh. like this:
Section files
FILE ./extrafiles/*
Section End
Directory like this:
Install_Dir\
extra_files\
app.exe
However, when the application is already installed, and I excute the set-up.exe again and select the same install directory,
the application will always remove all files in the install dir and then covering the directory totally.
Even if I skip the section in NSIS script, it still keep same.
So how could I stop the set-up.exe from removing files in install dir and covering it with new files?