Error while executing object_tracker.py in COLAB

[AzureCHEM]

W0315 07:24:22.164951 140703536494464 object_tracker.py:83] Empty Frame
W0315 07:24:22.265901 140703536494464 object_tracker.py:83] Empty Frame
W0315 07:24:22.366825 140703536494464 object_tracker.py:83] Empty Frame
Traceback (most recent call last):
File "object_tracker.py", line 163, in
app.run(main)
File "/usr/local/lib/python3.7/dist-packages/absl/app.py", line 312, in run
_run_main(main, args)
File "/usr/local/lib/python3.7/dist-packages/absl/app.py", line 258, in _run_main
sys.exit(main(argv))
File "object_tracker.py", line 155, in main
if FLAGS.ouput:
File "/usr/local/lib/python3.7/dist-packages/absl/flags/_flagvalues.py", line 481, in getattr
raise AttributeError(name)
AttributeError: ouput

No result

Thank！