Azure App Services appSettings.*.json configuration

azure_appSettings.text

When you want to publish your app and using the Development configuration.

By default this loads Production.

Create an app service
Configure
  - AppSettings
    - Add
      - Name = ASPNETCORE_ENVIRONMENT
      - Value = Development
      - Deployment Slot Settings = true
        - Save
        
When overriding a json kvp,
Configure
  - AppSettings
    - Add
      - Name = Email:Setup
      - Value = [email protected]
      - Deployment Slot Settings = true
        - Save

Note:
When reading other settings from the appSettings.json file, make sure you check the Deployment Slot Settings box.