How to connect Azure SQL database from Python Function App using managed identity or access token

KevinLi ,

Up to now, I've been developing locally using the token, no issues. Now I've published the function to Azure. I am receiving an error:

AttributeError: 'NoneType' object has no attribute 'cursor'

 eventually pointing `cursor = conn.cursor()` in the stack trace. This same code runs perfectly on localhost with token. 

I have verified that the System Assigned Managed Identity (SAMI) is turned on, my user is SQL Admin, and the SQL User and Groups have been correctly added. 

I noticed that there is no env variable named "MSI_SECRET" under the Configuration blade of the Function.

1. Is this env var supposed to be visible when SAMI is turned on?
2. How should I troubleshoot this error?

UPDATE 1:

- I put some logging in after the Python function below. get_sql_connection() returns "None".

- It appears that the Azure Function is not picking up the SAMI.

- Any help would be appreciated. Thank you

Thank you