Kudu builds with flask-restful but the app fails with these messages in log:

2020-02-20T00:00:31.040211104Z [2020-02-20 00:00:31 +0000] [37] [INFO] Starting gunicorn 19.9.0
2020-02-20T00:00:31.041417315Z [2020-02-20 00:00:31 +0000] [37] [INFO] Listening at: http://0.0.0.0:8000 (37)
2020-02-20T00:00:31.042140722Z [2020-02-20 00:00:31 +0000] [37] [INFO] Using worker: sync
2020-02-20T00:00:31.045314753Z [2020-02-20 00:00:31 +0000] [40] [INFO] Booting worker with pid: 40
2020-02-20T00:00:31.175970911Z [2020-02-20 00:00:31 +0000] [40] [ERROR] Exception in worker process
2020-02-20T00:00:31.175991011Z Traceback (most recent call last):
2020-02-20T00:00:31.175995311Z File "/opt/python/3.7.5/lib/python3.7/site-packages/gunicorn/arbiter.py", line 583, in spawn_worker
2020-02-20T00:00:31.176007312Z worker.init_process()
2020-02-20T00:00:31.176010512Z File "/opt/python/3.7.5/lib/python3.7/site-packages/gunicorn/workers/base.py", line 129, in init_process
2020-02-20T00:00:31.176021012Z self.load_wsgi()
2020-02-20T00:00:31.176024212Z File "/opt/python/3.7.5/lib/python3.7/site-packages/gunicorn/workers/base.py", line 138, in load_wsgi
2020-02-20T00:00:31.176027412Z self.wsgi = self.app.wsgi()
2020-02-20T00:00:31.176030512Z File "/opt/python/3.7.5/lib/python3.7/site-packages/gunicorn/app/base.py", line 67, in wsgi
2020-02-20T00:00:31.176033612Z self.callable = self.load()
2020-02-20T00:00:31.176036612Z File "/opt/python/3.7.5/lib/python3.7/site-packages/gunicorn/app/wsgiapp.py", line 52, in load
2020-02-20T00:00:31.176039712Z return self.load_wsgiapp()
2020-02-20T00:00:31.176042812Z File "/opt/python/3.7.5/lib/python3.7/site-packages/gunicorn/app/wsgiapp.py", line 41, in load_wsgiapp
2020-02-20T00:00:31.176045912Z return util.import_app(self.app_uri)
2020-02-20T00:00:31.176048912Z File "/opt/python/3.7.5/lib/python3.7/site-packages/gunicorn/util.py", line 350, in import_app
2020-02-20T00:00:31.176052112Z import(module)
2020-02-20T00:00:31.176055112Z File "/home/site/wwwroot/application.py", line 4, in
2020-02-20T00:00:31.176058412Z from flask_restful import reqparse, Api, Resource
2020-02-20T00:00:31.176061512Z ModuleNotFoundError: No module named 'flask_restful'

The fix is to correct flask-restful to flask_restful. I don't have permissions to submit a pull request so someone needs to do this.

(I spent many frustrating hours troubleshooting this issue -- and this was my first Python deployment to Azure App Service)