Denzjos,
Could you check if this script was actually authored by Ofnuts?
As far as I know, Ofnuts has a Luminosity plugin, but it is found in the menu: Select - Luminosity.
I also have this script that you referenced in the same menu, but I don't think it was authored by Ofnuts, but I could be wrong.
PS: I just checked, this script you mentioned was written by Tin Tran.
Could you check if this script was actually authored by Ofnuts?
As far as I know, Ofnuts has a Luminosity plugin, but it is found in the menu: Select - Luminosity.
I also have this script that you referenced in the same menu, but I don't think it was authored by Ofnuts, but I could be wrong.
PS: I just checked, this script you mentioned was written by Tin Tran.
.....
Samj Portable - Gimp 2.10.28 - Win-10 /64.
Samj Portable - Gimp 2.10.28 - Win-10 /64.