HP 39GS Cas-Enabler aplet

[WinterStorm]

Hello, this is my first post here, after 10+ years of lurking.
I recently discovered a number of very cheap HP 39GSs on a big Chinese marketplace, and promptly purchased one.
Then I tried the CAS-Enabler aplet, but it looks like it doesn't work.
Is that aplet working on the 39G only, or I've missed something, given I'm more used to the HP 50G?
Thanks in advance for any explanation.