I don't know if this will help, but, there is a page about using Script-Fu (with GIMP) on the GIMP site.
https://www.gimp.org/docs/scheme_plu...t-fu-gimp.html
Unfortunately I didn't read it. It's all Greek (not really, but that's the expression) to me. I really do not understand it.
Edit/
Well, I went back and read over it and it doesn't
really seem to tell you anything about installing the script. So - I looked into it further and found this bit:
https://www.gimp.org/tutorials/Asset_Folders/
I hope I'm helping.
/Edit
__________________
Ahhhh, the vagueries of the aging mind. Wait.... What was I saying?
Carbonite <----- GitHub main module (Maps ONLY) download link. The other modules are also available on GitHub.
Carbonite-CLASSIC<----- GitHub link to Carbonite Classic. Thanks to ircdirk for this!