AttributeError: type object 'Settings' has no attribute 'QPKG'

[ZakiG]

When I tried to extract the QNAP img file, I encountered the following error:
Traceback (most recent call last):
File "./bin/qdk2", line 88, in
main()
File "./bin/qdk2", line 82, in main
c(args, extra_args).run()
File "/home/xxxxxx/firmware/QNAP/qnap-utils/qdk2/python/qdk2/extract.py", line 99, in run
self.extract_image(self._args.file, directory)
File "/home/xxxxxx/firmware/QNAP/qnap-utils/qdk2/python/qdk2/extract.py", line 71, in extract_image
check_call(['tar', 'xf', Settings.QPKG, '-C', d])
AttributeError: type object 'Settings' has no attribute 'QPKG'

I looked at the code, and it didn't seem to have a QPKG attribute in setting class.
So how to solve it?
Thank you