Does anybody know how extract text script from Crescendo?

[ever17]

I want port text from English version to Crescendo～永遠だと思っていたあの頃～Full Voice Version and translate new scenes.
But to do it I need extract scripts that looks like encrypted in .ISF files
Engine is IKURA GDL, tools that I found online doing nothing or work"?" - but I don't find a method to get text
Here tool that try to extract text, but I don't get any text (Maybe I doing something wrong). _/(T.T)\_
https://proger.me/vn/old/?lang=en&lnc=1#ikura+gdl+/+crescendo