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If the App Service doesn't find a custom command, a Django app runs a default read-only app, located in the opt/defaultsite folder. You can control the container's startup behavior by providing a custom Gunicorn startup command. To do this, kindly take a look into this document for detailed steps.
-App Service looks for a file named wsgi.py within your app code, and then runs Gunicorn.
App Service ignores any errors that occur when processing a custom command file, then continues its startup process by looking for Django and Flask apps. Also, kindly review the startup file is deployed to App Service and that it doesn't contain any errors.
Note that the Python extensions for App Service on Windows is deprecated in favor of a direct deployment to App Service on Linux. So, leverage App Service for Linux rather than a Windows-based instance. Also, ensure that the Python module is correctly set requirement.txt and include below line of code as first line in requirements.txt file “ --find-links wheelhouse”.
Kindly let us know how it goes for further investigation.