Scenario: You test the Logic app in a development environment. The following error message displays:
'400 Bad Request'
Troubleshooting of the error shows an HttpTrigger action to call the RequestUserApproval function.
Note: If the inbound call's request body doesn't match your schema, the trigger returns an HTTP 400 Bad Request error.
Box 1: function -
If you have an Azure function where you want to use the system-assigned identity, first enable authentication for Azure functions.
Box 2: system-assigned -
Your logic app or individual connections can use either the system-assigned identity or a single user-assigned identity, which you can share across a group of logic apps, but not both.
Reference:
https://docs.microsoft.com/en-us/azure/logic-apps/create-managed-service-identity