Unable to run smallest windows service in Python

According to this answer I created a smallest Windows service in Python.

Then I ran successfully:

python.exe smallest_service.py install

and

python.exe smallest_service.py start

with error message

Starting service SmallestPythonService

Error starting service: The service did not respond to the start or control request in a timely fashion.

My Python version is Python 3.9.6

pip freeze
pypiwin32==223
pywin32 @ file:///C:/Users/me/Downloads/pywin32-301-cp39-cp39-win_amd64.whl

How can I fix it?

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