As rich mentioned, use another free program. Paint.net is a free program and has an option to search for all .8bf files on your computer. Most of them work with paint.net.
I've tried to linked paint.net with the nikplugin.py in gimp 3.0.2-1 but that doesn't work. With gimp 2.10.38 and shellout.py that was possible.
https://www.getpaint.net
I've tried to linked paint.net with the nikplugin.py in gimp 3.0.2-1 but that doesn't work. With gimp 2.10.38 and shellout.py that was possible.
https://www.getpaint.net