the KELF file to be bound is expected at program cwd under the name boot.kelf
So let's say you run the program from: mass:/APPS/DONGLEBINDER.ELF
DONGLEBinder will expect the kelf file at mass:/APPS/boot.kelf (Case sensitive!!!)
With the update I made today (realized I did not post this program here while doing so) the program may also rebind already bound boot.bin from other dongles