How to encrypt .PAK or package file?

Development Programming & Scripting
7

I dragged and dropped UnrealPak.exe followed by .pak file and added -encrypt command at the end but it said:

LogPakFile: Display: Added 0 entries to add to pak file.
LogPakFile: Error: No files specified to add to pak file.

I’ve created a short video to demonstrate the problem I have:

Thank you for your help.