can't start the program

[sh2515]

hi
I run the program but get the following
{'--blank-threshold': '0.97', '--debug': False, '--dpi': '300', '--face-up': 'True', '--keep-blanks': False, '--keep-tmpdir': False, '--post-process': False, '--tmpdir': None, '--verbose': True, '<pdffile>': None, 'pdf': False, 'scan': True} Temp dir: /tmp/20191123_210921 Traceback (most recent call last): File "/usr/local/bin/scanpdf", line 11, in <module> sys.exit(main()) File "/usr/local/lib/python2.7/dist-packages/scanpdf/scanpdf.py", line 402, in main script.go(args) File "/usr/local/lib/python2.7/dist-packages/scanpdf/scanpdf.py", line 360, in go self.run_scan() File "/usr/local/lib/python2.7/dist-packages/scanpdf/scanpdf.py", line 76, in run_scan device = os.environ['SCANBD_DEVICE'] File "/usr/lib/python2.7/UserDict.py", line 40, in __getitem__ raise KeyError(key) KeyError: 'SCANBD_DEVICE'