python3.6.7 and pyinstaller with upx, but it returns "UPX is not available"

Question

On my computer, I just have one python environment, it is python 3.6.7. And I want to use upx to resize my exe application. So I have copied the upx.exe to the folder of pyinstaller.exe.

But when I run my command, it returns "UPX is not available".

C:\Users\98082>pyinstaller --windowed  CreateChipPack.py
315 INFO: PyInstaller: 4.10
315 INFO: Python: 3.6.7
316 INFO: Platform: Windows-10-10.0.22621-SP0
317 INFO: wrote C:\Users\98082\CreateChipPack.spec
394 INFO: UPX is not available.

I really appreciate your help.