Article your pointing to doesn't have anything about Manjaro, also upwork doesn't provide any binary\package for ArchLinux or Manjaro. So there is no support for Manjaro\ArchLinux?
Hello, I am using manjaro. There is an AUR for the upwork desktop app. I just built it from Pamac, and it works well.
You probably have it already enabled but if not, you need to enable AUR support from Pamac's preferences.